75gr – 77gr (part 1 of 2)

(heavy on TAC powder loads & mk262 clone data)

-- 75-77gr reload info --

(copy of emailed from Ramshot re: 75 gr Hornady BTHP 5.56 load info.. not published data since "NATO" pressure info)

This is an email i got from someone at Ramshot. I thought yall might find it helpful.

Caliber: 5.56mm x 45 NATO. (.223 Remington)

Pressure spec: MIL<58700Psi“Casemouth”=<62000Psi/chamber=CIPInternational <4300bar/62350psi

Barrel length: 20” (For 16” barrel reduce velocities by 5 to 6% ca 150 Fps)

Powder: Ramshot – TAC.

Bullet weight: 75 grain HP.

Start load: 22.1 grains (2525 – 2625 Ft/p/sec)

Maximum load: 24.5 grains (2750 – 2850 Ft/p/sec). <62000 Psi

The NATO 77gr load is very hot. I wouldn't load to that spec. Add heat from rapid fire, and maybe a 90 degree day in the summer and pressures ramp up quick on an already hot load.

It does about 2,848fps out of a 20" barrel. Most SAAMI data tops out in the 2,700 range.

Regardless, any load at or around 2,800 with a 77gr bullet is beating up the brass. I wouldn't call it a dangerous load, but definitely hot. You can see it in the primers. They begin to flatten. They definitely look different than primers from a SAAMI load. Ignore these High power nut jobs who load 75gr+ bullets at nearly 3,000fps. Some have gotten kabooms in the summer with a load that worked in winter. There's no room for any amount of bullet setback. Just too many variables.

Just not worth it. Load to a lower speed and you'll be fine. Loading past 2,800 to get a few more yards of "terminal performance" ?? Just the fact that it is a 77gr bullet makes it more effective than military ball at ALL ranges. Hornady TAP FPD is loaded in the 2,650fps range, and there's no doubt that it's effective and safe. This is one of those "be happy with what you've got" type of things in my opinion. You get superior effectiveness, more range and more accuracy. Even without the extra NATO fps.

I really like TAC. Good powder. It is very, very, very clean burning powder. When they say 2 patches and clean, they aren't kidding. A shooting session with TAC is like shooting literally 50% of the volume with a different load or factory ammo in terms of barrel and action filth afterward. It is also more speed appropriate for the mid to heavy .223 bullets out of 16-20" barrels.

Ah, quick story. Was thinking about making a thread about it but haven't gotten around to searching the forum to see if it hasn't been posted already.


For one, the military uses huge lots of primers that get tested in advance. Keep that in mind as I tell this quick story.

Bought some CCI BR4's.

I would shoot strings, and out of the blue - I'd have 1 shot go 200-220fps faster. Started scratching my head. Thinking....bullet setback? So I was feeding this into the chamber by hand and closing the bolt behind it and then tapping the forward assist. Same thing. HMmmm? Could be be my weight? Scale messed up? Nope. I have a check-weight set and the scale gets checked every use and has never been more than .1gr off at any weight. Each charge is weighed by hand during work-ups and I have never had that kind of an anomaly before.

Turned out it happened a couple more times and I called it quits as I was on my mid-range charge. Didn't want to risk it.

Then, earlier this year in an issue of Handloader magazine, the author was doing a .223 primer test for accuracy. See if there's any practical difference between the various primers. Sure enough, he came across the same problem and was puzzled by it. He would get 1 shot out of a 5 shot string go 200fps faster. Ruining groups and killing the ES/SD of a load. Not to mention, being unsafe.

Haven't heard anything about that since. But that happened with the CCI BR4. I wonder if a defective lot had been released? No primer should have that kind of fluctuation out of no where. I need to dig up the article and scan it.

Anyway, that's my story. Now, imagine loading that 77gr load to over 2,800fps. Add in a hot barrel from a shooting session, add in a hot day ...come across a primer like that giving you 200fps. Add it all together and you've got a load that could be 350fps hotter or more. KABOOM! I know a hot day and a hot barrel can add 100fps from all my chronographing. That alone is reason to stay at SAAMI max or a touch lower. Let along a freak defective primer, a slight bullet setback or some other factor adding dangerous pressures.

Always build in some safety in your loads. Because it isn't a perfect world. The military does insane amounts of testing on their components. They force their suppliers to do real world large volume batch testing of everything. Also, all their rifles are proof-load tested then MPI tested, they also use the strongest gun barrel steel and have big sloppy chambers.

FPS isn't everything. Hits count. Badguy isn't going to care when he gets smacked downrange by a 77gr Nosler whether it is doing 2,400fps or 2,475fps. And if this is for competition, these hot loads are absolutely not the most accurate.

Proceed with caution. Your eyes/face/fingers/life isn't worth a few fps.

Both Reloader 15 and RamShot TAC are great powders. I prefer the latter using the identical load Black Hills developed for the SOPs snipers Mk262 Mod 0 and Mod 1, the only difference being the Sierra 77 BTHP SMK bullet used in the Mod 1 is cannelured. Keep in mind this heavier bullet is only intended for barrel twists 1:7, 1:8 and 1:9. My SRP has a 20" Douglas SS barrel with a 1:8 twist and easily shoots a .5 MOA

For the Sierra 77 gr BTHP I prefer 23.1 grains of TAC for accuracy, although I am using a 20" barrel w/ 1:8. The max. recommended load on this chart is 24 gr. TAC, although I get max. accuracy with a velocity of 2650 with this bullet

I exactly duplicated the M262 load with TAC, but it is very hot and I changed to N540.

It was 26 grains of TAC driven by a Magnum Primer with the Nosler cannelured 77 grain bullet. This came out at over 2750 fps from a 16 inch barrel. I didn't have a problem with it but some of the primers were flattened.

To dup the M262 using availible powder I use the much more expensive N540 and Varget.

That said I use more TAC than any other powder because there is no reason to load this hot for plinking, triggertime, drills, and even shtf with 62 grain bullets.

I Just got off the phone with Black Hills, they use a MIL spec primer he believed they were #34's on their reloads but their new ammo is factory primed..........Winchester.

(note to self: as of March 2008, BH uses Winchester factory brass pre-loaded with winchester sr primer!!)

I load the 75 grn hornady HPBT #2279 for my colt Elite too. I use 20.6 grains of Accurate Data Powder 2200 and seat the bullet to 2.248. I can get groups at 200 yds under 1.5 inches off the bench with this load.

In lieu of an OAL gauge, you can use the old tried and true method of blackening a bullet with a felt tip marker, seating it in an *empty* case, and chambering it. The lands will leave marks on the bullet. Seat the bullet in a bit deeper, blacken it again, then re-chamber it. Repeat until the bullet no longer shows marks. That's the max OAL for *your* barrel. Some bullets shoot better set right into the rifling and some are best set .020" or .030" off the rifling. You'll need to experiment. If you set it into the rifling, back off the powder charge a bit and work your way back up.

In the long run, a Stoney Point OAL gauge will make your life a lot easier.

Black Hills’ 75 grain Match HP (hollow point) ammunition is loaded with Hornady’s 75 grain BTHP Match bullet with a cannelure (referred to as the "T1C" here on AR15.com) and both the red box and blue box loads have a crimp at the case mouth. Both loads are charged with “ball powder.” The nominal OAL for the red box cartridges ran around 2.245” and for the blue box cartridges it was closer to 2.250".

Black Hills does not perform a “trim to length” operation on the resized cases used in the blue box ammunition. As a result, many of the cases are longer than the SAAMI recommended maximum length of 1.760”. Several of the cases that I measured had a length of 1.775”. This could potentially cause problems in a barrel with a minimum length chamber, though no malfunctions of any kind were experienced during the testing of this ammunition. (Using a Sinclair chamber length gauge, I determined the chambers of my Colt barrels have a length of 1.780”.)

(AR Loads for Highpower)

What works depends on what your rifle likes. This means you must work on load development. I would work with a medium burning powder and experiment with different charges and bullet types. If you are only shooting at 200 yards, look at 748 with 68/69's. If you are shooting over the course, look to 77's at 200 and 300 (Imr 4895 or RE-15) and 80's at 600 (same powders) (presuming that you have a proper twist on the rifle barrel). Some guns like a-max's: you wont know until you try different bullet types and compare your targets. I recommend moly-coating: it improves velocity and makes barrel cleaning easier. Loading for the AR is a little different than for the M-1. With the AR, you will see flattened primers: that is ok: avoid blowing your primers. You may want to consider selecting cases: commercial cases seem to work best at 600 yards (slightly bigger case capacity). Unlike the m-1, there isn't one magic load (i.e.: a national match load): the accuracy comes from hard work and load development. Do your homework and the results will show down range.

75 Gr. Hornady W/Varget

I have used 25.0grs w/ non-moly coated bullets, WW Primers, WW & REM cases, seated to mag length in a Colt HBAR. I only switched to Rl-15 because of a good deal on several cans and one limited test w/scope attached for 100m accuracy evaluations. The difference was marginal, but the deal was substantial!

75 Gr. Hornady W/Varget

I've used 25.0 Varget in GI cases for Hornady moly 75's and Sierra moly 80's for 600. That's where I'd END. You should be happy somewhere in between 23.5 and 25. I've shot the 75's at 600, and they'll do okay, but nowhere near as well as the 80's.

75 Gr. Hornady W/Varget

Dave: ditto's on the varget loads, I settled on 24.5 because more didn't help accuracy but did noticeably increase primer flattening. I also have a lot of crunching of powder even with vibrating the filled cases at 24.5. How have you found the 75 a-max compared to the 80's? My guns shoot them very well at 600 and I decided to stick with them. I have heard one of our shooters got a very impressive 600 yard score with the 77's at MAG(!) length in his match ar - a 198 in practice. So in his gun at least, they don't mind a long jump. Don't know how it will do for him in matches but I'll be watching.

75 Gr. Hornady W/Varget

I was shooting the 75 NM bullets, not the A-Max's, although the fellas I talked to that had original 1-9 twist (Armalite) guns said the A-Max's were the Primo 600-yard bullet. I got an e-mail a while back that said a fella won a 1,000 yard match in Wisconsin with the Hornady 75 NM's, but they were subsonic.

You can cut a 1/4 in slit ( or longer or shorter, i dont load data for 22 cal guns.) down the neck of the case using a hacksaw or dremel. You just have to cut it enough so the bullet will slip in easy but not drop to the bottom of the case.and you slowly put it in the gun and close the bolt. remove the round out the gun carefully. and your and that should give you your OAL.if you cut the slit deep enough you will usually see how much space youll have between the bullet and the powder. I usually use a medium crimp on my rounds, i load 30-06 and 7.62 bolt actions. I set my crimp die so that when the collets close you could still fit a little thin paper or credit card between them ,thats about med. crimp. I usally get 1/4groups or less at 100yd using oal bullet depth and med or lite crimp, sometimes I've shot 3 round hole to hole ,well almost hole to hole.

I was able to load some rounds to test 68gr vs. 75gr bullets in my .223 Remington 700 Tactical with 1:9 twist barrel.

The results show that my Remington clearly prefers heavy 75gr bullets over the lighter ones.

Bullets used: Hornady 68gr BTHP Match & Hornady 75gr BTHP Match.
Powder used: Varget, except one target as noted. (It was shot with rounds that were loaded with leftover BenchMark powder and 75gr bullets).
Primer used: CCI 400 Small Rifle
Brass used: Winchester, Neck sized, No crimping applied.
All shots were fired at 100 yards range, from bench-rested position.

With 75gr bullets, 24gr AND 24.9gr of charge weight seems to be working the best.
I will load more rounds at those two charge weights and play with different seating depth to see if that will make the group even smaller.

With the 68gr bullets, 24.6 gr of charge weight seems most promising.
I will play with that weight at different seating depth as well.
Hopefully, I can find the THE sweet spot for both 68 and 75gr loads.

I have the 7th edition Hornady manual. The data for 75gr A-MAX in .223 is:

Rifle: Colt AR-15, Citadel Bbl
Barrel: 20", 1-9" twist
Case: Winchester
Primer: Winchester WSR
COL: 2.390" (75gr A-MAX #22792) - SINGLE SHOT ONLY
Max case length: 1.760"
Case trim length: 1.750"

Powder max charges:

2600 fps

IMR3031 - 21.2gr
AA2495 - 21.8gr
Viht N-135 - 21.8gr
AA2520 - 22.5gr
Varget - 23.5gr
Viht N-140 - 23.6gr
Viht N-540 - 23.6gr

2700 fps

H4895 - 23.3gr
RL-15 - 24.1gr
WIN 748 - 24.0gr
BL-C2 - 25.2gr#

Hornady's best results came with Viht N-140. Viht N-135 and AA2495 were excellent, but could not match N-140.

I found that the max charges are substantially lower than Hodgdon for example. The ideal in my rifle for this bullet is 24.2gr Varget, which shows no over-pressure signs and is well within Hodgdon's max loadings.

About 8 years ago I conducted load development with the 75 Hornady in a match AR. I tried N135, N140, and AA2520.

I decided I liked N140 better and have been using it in my service AR’s since then.

I now use a load of 24.5 grains, and depending on the rifle, 24.5 grains gives me an average velocity just at, or a little less than 2700 fps.

Since match ammo is often shot on 100 F days, I am not interested in pushing stuff that will pierce or blow primers. So I decided 2700 fps was a good not to exceed velocity in the AR with a 75 grain bullet. Accuracy is outstanding.

However, if you are looking for more suggestions, any of the IMR 4895 burn rate powders will perform excellently in the AR. I would suggest H4895 as I am told it is short cut, but IMR 4895 or AA2495 will give excellent performance.

I know some folks used IMR 4064, but that is long grained and does not meter well in my Dillion progressive. I tried AA4064 but it is even slower than IMR 4064 and I could not get decent velocities with the stuff. Shot little bug holed groups with 69’s though.

M15A2 Armalite 1:8 Stainless Wilson Barrel

75 gr Hornady Match 24.5 grs N140 wtd LC 84, WSR, OAL 2.25"
6-Sep-99 T = 92 °F
Ave Vel = 2677
Std Dev = 8
ES = 30
Low = 2662
High = 2692
N = 10

75 gr Hornady Match 24.7 grs N140 wtd LC 84, WSR, OAL 2.25"
6-Sep-99 T = 92 °F
Ave Vel = 2732
Std Dev = 25
ES = 86
Low = 2686
High = 2772
N = 8
primers flattened Max load

The best powders I've found for the .223 and heavy bullets are: H335, BLC2, WW748, WW844,WW846, H322 and IMR4895. All but the IMR are ball powder and meter very well in a progressive press.

Here are a couple of different loads that I shoot out of my GA gun and also my 1 X 8 AR. These loads are safe in my gun.

77 GRN Sierra 23.0 grn RL-15
77 GRN Sierra 23.5 grn RamShot TAC
69 GRN Sierra 22.5 grn VVN 135
(This is my most accurate load out of any of my 223 rifles.)

Try these loads and see if they will work

give a try

69 smk
25.4grn varget
cci br4

I subscribe to the notion of trying 69 gr SMKs. The load I use with 69-ers is 24.8 gr Varget for a 20" barrel 5.56 mil chamber 1:7 twist.

And when you do load development with the 223 your final sweep should be done in 0.1 gr increments to find the sweetest of the sweet spot.

I load my 80gr SMKs with 24.5 gr of Varget seated out about 0.015-0.020 from the lands. The JLKs, I seat into the lands by about 0.015. In the rifles that I have shot them in, the 77gr and 80gr bullets seem to have a special affinity for 24.5gr of Varget.

I bought 1k of once fired Win cases that had been full sized and trimmed, and then I weight sorted them into .5 gr. lots. I came up w/ 200 92.5-93g, and then another 200 93g-93.5g. I've been working w/ the lighter lot. I haven’t done any other prep, other than full sizing for the first firing, and then collet sizing for subsequent firings. There has been no noticeable difference between the fl and collet sized cases, yet.

The benchrest crowd usually likes to select the slowest twist that will statically stabilize the bullet they want to shoot. A faster than required twist can induce a dynamic instability if the bullet is not perfect.

In my opinion, the 1:8 twist is entirely suitable to statically stabilize the long-for-caliber bullets in the 75-80gr weight range. I have shot many thousands of them out of 1:8 twist barrels and never experienced any tendency to keyhole.

I will say the required spin rate to stabilize the rifle is made up of muzzle velocity and twist rate, so if your bullet is too slow, the twist rate might not make up the proper spin required.

I always run my long bullets at higher velocities, but that's mainly because I shoot at long distances.

I use the 80gr JLK and the 80gr SMK exclusively in my match AR. I load my JLKs about .015 or so in the lands. I also put a hefty load of Varget behind the bullet. In my experience, Varget is a powder that gives excellent consistency at full or near full loads. Your 24.0 is a little less than what I use, but since your bullet is so far in the case, you may not have a choice.

VLD's can be a pain in the @ss to get right! I would start with the SMK and known loads to test the rifles performance! SMK's are much more forgiving and will quickly tell you if your rifle will shoot. If it shoots SMK's well it may be worth going threw the trouble of getting the VLD's to work. VLD's don't "JUMP" well, btw.

If your holes are nice and round then your bullets are statically stabilized, you just need to find the load that your barrel likes. Have you measured the chamber with a Sotney Point or something similar? I do that for all the (2) types of bullet I use, that are not magazine length. Then I play the how-close-to-the-lands game with the SMK, and the how-far-into-the-lands game with the JLKs until I get it right.

But I should note that by this time, I am less than .5MOA already, this is final tuning for my loads.

And then there is the possibility that your rifle just won't shoot regardless of the load; something else may need attention.

Might want to browse around over on nationalmatch.us... they have a lot of good load data for about any bullet you can conceive in a .223 Rem for 600+yd shooting. I've seen some people campaign the .223 fairly successfully out to 600yds; the only person I've seen myself that shot a .223 @ 1k was using 77gr Lapuas. They shot very well on the 600yd day @ FCNC (he scored 3rd F/TR for the day with them), but he was hemorraghing points left and right @ 1k (Raton had some surprisingly twisty winds). Another person there for the SOA match shot a .223 in the Fullbore category (300/500/600/900/1000yds) and did fairly well with it (took 2nd Expert in the grand agg). From the sounds of it, his barrel is throated looooong, so take that into account.

I dont know what the rules are in your area, do you have to shoot 80gn sierras like we do? They are very good for 1000yds, but the 80gn Bergers are slightly better if you have trouble with bullets going subsonic before the target, they will get there slightly quicker than the Sierras if your velocity is marginal. They will go well in the 7" twist at the velocities you will be doing. Another powder to try if you want to get your velocity up is Vihta Vouri N540. It is a high energy powder and might help get a tad more velocity if you need it.

I'm new to this forum, but I have been shooting F-class for a few years now. I shoot .223 at 1000 yards using my "enhanced" AR-15. After several bullets, I have settled on the 80 gr JLK VLD design, which I moly-coat. I load this fine bullet on top of 25.7gr of Varget in a Lapua case with a Remington 7 1/2 primer. My measured MV is 2860fps. The bullet is loaded very long and is about .010 into the lands.

I use the Sierra 80gr bullet for the 600 yards range, but will be standardizing on the JLK 80 when my supply if 80gr SMK runs out.

I shoot 223 at 1000 yards, using a Savage 12FVSS with stock barrel (26" 1 in 9 twist).

Just working on a new load, but last testing I did at 1000 using VV N140 and 75 Gr Amax was a 73.6 over 15 shots - light winds that day.

At the ORA Mons championship recently in Borden, the TR was won by a 223 shooting 80 gr bullets.

Been testing my new Stevens Pac nor 223 (7 twist) and 75gr Amax. Varget shoots better then Benchmark (not by much). CCI 450 is working much better then BR4 in the cold.

Took this rifle to plink at 1000m and had no problem keeping the hits inside a 1/2 X 3/4 MOA rock (size based on mildot subtension) on a relatively calm day.

The best I ever "made" to approach the Black Hills with the
Sierra 69 was with 24.0 gr. of BLC-2, a Federal 205m match primer

My current load for the 75s is 23.8 WW 748 loaded to a OAL of 2.250 for the BTHP and 2.390 for the A-Max. This is straight out of the data sheet sent to me from Hornady.

Since most don't have the sheet, here is the mins/maxes for different powders....

IMR 3031 20.0 to 21.5
N135 20.9 to 22.1
AA 2495 20.0 to 22.3
AA 2520 20.7 to 22.8
H4895 20.9 to 23.3
N540 22.1 to 24.0
N140 21.8 to 24.0
VARGET 21.5 to 24.0
WW748 21.7 to 24.0
RL-15 21.7 to 24.0
BLC-2 22.8 to 25.6

I have a .223 VSSF Rem. With a factory 26" barrel that has served to shoot around .5 to .75 with full resized and factory ammo. I sometimes would beat that if I would seat out a bit more than my AR-15 clips would allow but anyway it was heavy to handle in a (tactical coyote) situation. (you see coyotes can count coup) I decided to cut off 6" and was sweating the flutes. it looks a bit funny at first but the first group out of the box was .21". There is something about a 20" barrel in this caliber! My Bushmaster AR 20" stock will shoot .5 to 5/8 also.

Or is that my imagination. Anyway it has become quite handy now! Tackies take note. By the way In case your interested I did it with a "chop saw" and counter sunk the crown with a cone shaped dremmel tool.

Nothing like precision work. We have crowning tools but we wanted to see how much difference there really was. Now we're afraid to proceed to the special tools for fear of ruining it. Speed about 3100fps. 55 grain V-max with Varget load on the can.

For 69gr SMK's

My Favorite load is Reloader 15 with 24.0 to 24.8 grs. Extremly accurate.

Varget with 24.0 to 25.0 grs. Very accurate but might not get good bullet speed with it.

AA2460 23.5 to 24.0 grs. a ball powder and very accurate.

H4895 24.0 grs. Shoots very well and accurate.

I use Lake City brass with Rem 7 1/2's or CCI BR primers. I prefere the Remington 7 1/2's and they work well in my AR. These loads could be slightly compressed when seating the bullet. Not as much as a 77 gr. SMK though.

It is rumored that Black Hills uses Ramshot TAC powder in their 75 Gn. loads...but this is not confirmed.

I checked my notes, and Hornady recommended to me that to duplicate the Factory 75 Gn. FMJBT "Match" load, use 24.0 gns. of WW748 with any quality commercial small rifle primer. I use Winchester primers. This load is a little softer than TAP, but I don't think the BG will notice.

I've had really good luck with Reloader 15 and Ramshot Tac with the heavies.

I too have been on an "equivalent point of aim" quest to match my MK262 Mod1 seconds.... Those real deal "seconds" are too expensive, so I try to clone them with cheap(er) reloads...

So far I have had good results with Accurate Arms 2520 powder and CCI #41 military primers. I don't have my grains number handy, but will look it up later...

One thing seems to be sure after several threads on TOS about this round, the powder in an MK262 Mod1 looks NOTHING LIKE the TAC powder, so don't get your hopes up. They bulk buy it anyways... so it is a custom blend.

Be careful... the powder needed to get to an MK262 point of impact is a HOT ROUND. Watch for overpressure signs... I also like the CCI military primers as they do not pierce easily (like Winchester primers do...).

Good general rule...if it has a cannelure, apply a taper crimp especially for hard use ammo. If you are using match bullets like the Sierra Match Kings and you want the ultimate in accuaracy, don't crimp, but you may want to load one at a time with the bulluet laying on top of the Mag. follower (versus stripping it from the Mag.) so as not to get any setback from the bullet hitting the feed ramp.

I like varget for heavier bullets. I seem to use a good amount of powder for lighter bullets to get the velocities up. Varget seems to shoot better for me with hotter loads anyway.

You might also look at Vhita Vuori N133 with lighter bullets and N140 for anything over 69 grains.
VV powders are the cleanest burning I've ever seen. They are made with cotton cellulose rather than wood cellulose which is why they are cleaner and also a little more expensive.

Varget is a great powder, but it doesn't meter consistently. Great if you tricle your charges or use a Lyman 1200dps.

When using a Dillon powder measure with 22 caliber bullets, here are some things you can do:

-- polish the inside of the powder funnel.
-- dremel the inside of the powder funnel to give a longer less drastic curve to the funnel part and then polish it
-- whack the powder measure with your hand when the ram is down after each round

The problem with extruded powders is that they do not consistently form their air pockets. A secondary problem on small diameter cases is that they jam up in the powder funnel itself.

When you whack it (does not have to be that hard) when the ram is down after each round, you help settle the powder inside the powder measure chamber which gives you a more consistent set of air pockets and hence a more consistent charge weight. Ball powders are consistent as they don't exhibit a "pick up sticks" effect which causes varied air pockets and lack of consistency.

A small whack when doing 22 type cases (223, 204, 22-250, etc) when it is up in the powder die will help break the log jams that may appear.

The polishing and opening up and shallowing out the funnel angle in the powder funnel itself helps with the extruded powders jamming up.

Re: heavy 223 bullets - don't test them at 100 yards. Don't do it. You won't like what you see because you probably expect them to equal 55 grn bullets. These are NOT the same.

Test at 200 to 300 yards. Zediker discusses this in his book. Heavy bullets are deadly accurate, though they often do not "settle down" to group the same way you are accustomed to 55s grouping at 100.

You guys are right here is what I came up with 25 grain varget 75 gr bthp hornady I have reloaded 2000+ of that and have never had a problem it gives me about 2700 fps out of a 16".

I have used the Nosler's 77gr HPBT with Varget, I had OK luck with it. It shot good, but not as good as my Hornady 75gr HPBT load. My National Match has a 1X7" twist and Wylde chamber. The load I used was Remington brass, Rem. 7 1/2 BR primers, 24gr Varget and the bullet was seated to COAL of 2.259". Now this was safe in my rifle, but I would start lower and work my way up.

I have never used the Hornady 55gr V-MAX with cannelure, but I have used the standard bullet. I have used it in both my 1X7" twist AR15A2 NM and my Varmint rifle with a 1X12" twist barrel. The Varmint is a .22-250 Remington so that don't matter. In the AR15A2 it was almost the same load as the 77gr HPBT and out of the 1X7" twist shot real well. Rem brass, Rem 7 1/2 BR primer, 24.2gr Varget and bullet seated to 2.250" COAL. As I said before, this load was safe in my rifle, start lower and work up.

The COAL on them are 2.260" and I try to set my rounds as cloce to that as I can get, I have found that with Hollow Point bullets , with the differences in the point, that 2.258" or 2.258" will make sure the bullet nose has enough clearance in the magazine.

I hope that this helps, I have to say that the Varget and Vitha N 140 are my very top picks in heavy bullet loads in the .223 Rem/5.56X45mm NATO. I like them both because they aren't temperature sensitive, and they seam to be consistent from lot to lot. Be safe, have fun and good shooting.

(when asked why he didn’t list the Varget powder load above)

I didn't say it because it is a little over max load for the AR15. I shoot in NRA National Matches and as always we are pushing things a little hard.

I will say I had real good luck with 22.5gr Varget, Rem brass, Rem 7 1/2 BR, Hornady 75gr HPBT. This load isn't max, but it's at the top so start around 20.5gr and work up. Be very careful when you start to get into heaver loads.

I tell you two reloading manuals that I think is the best is the Hornady's and Sierra. They have more loads in more powders with match and varmint bullets. There are other ones out there, but I think that these two are the best. I hope this helps, be safe and really learn to load accurate ammo by reading some, if you take your time, do prep work on your cases by uniforming the primer pocket, deburring the flash hole, trimming the cases to the same length and using good quality brass, watching charge weight to +/- 10th gr. and the bullet seating you will find that you can get some very good groups.

I have used the Sierra 77gr HPBT for awhile, but switched to the Hornady 75gr HPBT match. They shoot better in my rifle but not by much.

A little info. Here Lapua now makes a 77gr HPBT, it's been out for almost a year. It is the longest bullet that can be loaded magazine length, and it has the highest Ballistic Coefficient in it's class. I have used them and they are great, the problem is finding them and they cost a lot more then the others. I got a supply of they when they were still in prototype stage, and I was very impressed with them. So if you see them give them a try.

(reply to someone using 77gr smk & RE-15 combo)

That should be a very good combo., there are a lot of High Power shooters that use it. The most poplar is the Varget, but Reloader 15 has a following. I uses it in the Berger 90gr VLD loads, it is one of the few powders that have the velocity you need and keep the pressure sane. It is a very good powder that can be used in a lot of loadings.

KyAR (experienced NRA match shooter)

(from NRA high power shooter)

There have been posts on Mk262 recipes before. I've posted the one I developed for my 18" SPR when I still had it.

NOTE: The following data exceeds SAAMI specifications and can be dangerous to use in certain rifles.

Sierra Match King 77gr BTHP
25.3gr Hodgdon Varget
LC Brass
Winchester SR Primer

Developed in a White Oak Armament 18" SPR configuration with a Wylde chamber.

Note: At the time, I was using Winchester SR primers. I would recommend Remington or CCI instead.

Any load that will give you Mk262 performance will exceed SAAMI specifications for .223. Thus, you're not going to find any published commercial data that will meet Mk262 velocities.

You shouldn't use anyone's Mk262 'recipe' straight up.

If you want to make your own Mk262 clone ammo, you NEED to get a chronograph and work up the load appropriately. Don't kid yourself thinking you can just use someone else's recipe or the commercial data and guestimate the proper load to meet a specific velocity. The Mk262 pressures/velocities are pretty hot and you're going to need to carefully find the right load for your specific rifle. And when you do find the correct load for your specific rifle, you need to reconfirm the load everytime you go to a new lot # in bullets, powder, primers, or cases.

Also, that Nosler load quoted as mine was not confirmed to be 2650fps in an 18". That is my load I use in Service Rifle and it clocks 2740fps in a 20" Service Rifle barrel. I would estimate that it shoots 2650fps in an 18", but I have never clocked it in a 18" barrel.

(Warning: this is an over-book-published load!)

77 grains Nosler (25 grains TAC)
---> 2.255 OAL
1) 2821 35.4
2) 2786 0.4
3) 2832 46.4
4) 2800 14.4
5) 2799 13.4
6) 2745 -40.6
7) 2781 -4.6
8) 2776 -9.6
9) 2796 10.4
10) 2720 -65.6
High: 2832
Low: 2720
E.S.: 112
Ave.: 2785.6
S.D.: 33.2
95%: ±27.0

77 grains SMK 25 grains TAC 2.255 OAL
1) 2801
2) 2793
3) 2802
4) 2800
5) 2799
6) 2795
7) 2791
8) 2804
9) 2796
10) 2798
High: 2804
Low: 2791

1X8.....Ideal for the 69 to 80 grain bullet. As you can see, the load is a bit unpredicatable with >100 E.S. From my last test, 24.8 grains of TAC was the sweet spot I was looking for. Did not have a chance to chrono the new load but saw no differences with accuracy for a 10 shot group (<.73 MOA)

I've been working up a load in my 18" SPR build using 77gr SMK, Remington Brass, CCI and N140. Like the Sierra manual says, around 24.1g seems to be the sweet spot.

Colt 20" 1-7 HBAR and Bushmaster 24" 1-9
No pressure signs with these loads in my rifles...
I'd try a different Primer but winchester are the easiest for me to get.. I'd like to use CCI's but I haven't been able to fine them lately...

5.56MM 77 Gr Sierra BTHP MATCH 1-7” TWIST
INFO: FOR 1-7 twist

5.56MM 77 Gr Sierra BTHP MATCH 1-7” TWIST
Info: FOR COLT UPPER shot well at 100 yards

223 75 Gr Nosler BTHP MOLLY MATCH
COMMENT: shot well at 100 yards Out of 24" 1-9 twist Bushmaster upper

223 75 Gr Nosler BTHP MOLLY MATCH

It seems in some guns the hot rod loads shoot better groups and in HP it's dam near mandatory to have a High velocity loads that reduces wind drift at long range targets. Some of the pro's load a charge up until they blow primers and then back down, not recommending that, but hot is good sometimes. Remember 5.56mm Nato ammo is mil spec, not SAMMI spec, it's pressure is higher.. I use LC brass and IVI brass, so it is thick and tough.

I just loaded 100 rds of Berger 73Gr match with 24 Gr of RL15 just a side note RL 15 and Varget are so similar to each other they could be interchanged... I moved down to 24 Grs with the Burger 72 even though they weigh less then the 77 SMK for two reasons I've heard that burger has thinner jackets than Sierra's MK and it's a new bullet to me. I'll see how they preform. All of my OAL length is magazine length, I don't measure I just make sure they fit in the mags. As to the question how hot to load a round, if you use Military cases they will hold less powder but are tougher, if you use civilian brass they will hold more powder but are thinner and softer. So primer flatting and normal pressure signs will have to be the method, at the top end the smallest powder increase will push velocity and pressure a large amount.

I just shot Burger bullets for the first time in a NRA High Power match. They were very accurate. I loaded a 73 Gr burger bullet behind a charge of 24 grains of RL15 I used IVI 85 case and winchester Small rifle primer, no problems with pressure or any other kind. I loaded them to magazine length. As a side note I looked in the Hodgen loading manual and they have a listed load with the 75 gr bullet the load for 223 is 24.5 gr 4895 at 2905 check your loading data in a manual.

JickoRicko I'd change my brass from Fed (which have had major problems in 223 brass) to a Military case like LC or IVI, IMI etc. You will probably be able to reach your velocity goal of 2775 with less powder because of the small case volume

There was a guy in my squad and we were so frustrated that he decided to have me try his loads (24gr AA-2230 / 77gr SMK / Fed205m / LC case / OAL 2.244).

Man, now, we are in business..... the next 35 rounds, I've got 4-Xs, 6-10s, 14-9s etc.... very accurate

I found that primers DO affect velocities!! Significantly!! I never thought that it would be THIS significant.

Nosler Custom Comp 77gr HPBT
Chrono @ 12ft, Temp 60F
5 rounds avg, shot from 18" Mk12Mod1

24.8gr RL15, 2.25 OAL, LC06 cases
CCI #41 yields 2738 fps, ES 73/SD 28.2
CCI BR4 yields 2699 fps, ES 34/SD 16.3

25.3gr VARGET, 2.26 OAL, LC06 cases
CCI #41 yields 2767 fps, ES 89/SD 34.2
CCI BR4 yields 2707 fps, ES 33/SD 15.6

(from AR barrel maker www.arbarrels.com)

Differences in barrels can account for 100fps or more difference with the same load.

69gr SMK or 68gr Hornady work great in 1:9 twist barrels.
If you have a 20" long 1:9 barrel, you can usually get 75gr Amaxes to work too.

A 16" or 14.5" 1:9 barrel usually won't stabilize the 75's though because it does not make enough velocity so the 69's are the max there.

The tolerance for most standard grade factory barrels is +/- 1/2" on the twist rate.
Therefore, a 1:9" barrel can vary from 1:8.5" to 1:9.5" and still be called a 1:9" twist barrel.
The 1:8.5" barrels will certainly stabilize the 75 Amaxes while the 1:9.5" barrels won't.

Velocity is a factor in the stabilization formula.
Longer barrels make more velocity.
Therefore, given the same cartridge and loading, longer barrels do not need to have as fast of a twist rate to stabilize the same length bullets.

Depending on the tolerances of YOUR barrel and YOUR load, YOUR barrel may or may not stabilize 77-80gr bullets.
The way to find out is to go shoot them through YOUR barrel.

I recommend doing this testing at the lowest altitude and on the coolest day you may ever shoot them as higher altitude and warmer weather also help stabilization.

I have loads for 69-80 Sierra. You might want to try 24.5gr WCC 846 with the 80's. With AOL 2.435. Now the 69gr Sierra I wanted a little more ummph so I used 24.5gr of WCC 844. Which is H335 equv. I quit buying the 69gr Sierra because they got so expensive. I went to the 75gr HPBT match Hornady. These I load with 24.7gr of WCC 846. I have 60lbs of 846 and 32lbs of 844 and make good use of it. I shoot 1X8 twist barrel. Now these loads work for me. I'm currently an NRA Master and got that way using these loads. I'm also starting to work with the 75-Amax to see if it helps me in the Off-hand position. I load these the same as the regular 75 but with an AOL of 2.390

I use 24.0gr of RL15 for the 77gr SMK/Nosler for my short line loads. I never really put much thought into it. Loaded some up. Shot a few groups. Did some chrono testing. Stuck with it. Shot no worse than MOA so I used it.

I pretty much use 24.0gr of RL15 for any 75-77gr bullet in LC brass. Everytime I do, the load shoots MOA at worst (out of a competition grade SR barrel).

I got great results with 77SMK winchester brass and 24 gr TAC COL 2.26

This weekend, I shot Nosler 77gr HPBTs in a service rifle match. LC brass, 24.0gr TAC, CCI 450, COAL 2.260", chronographed at 2740fps out of my 1-8 twist 20" barrel. With a 200 yard zero, my come-ups were 2 MOA at 300 yards, 11 MOA at 600 yards.

les baer .223 police special
16 inch barrel with 1 in 8 twist
77gr sierra hpbt match
coal 2.255

Average of 5 rounds using chrony chronograph, my goal was to hit 2,750 fps this would give me a max spread of 4 inches from 0 - 250yrds if I zero at 50 yards. Also will give me a frag range of close to 200 yrds.

elev = 5,000ft
temp = 75 degrees

lapua brass
cci br-4
26 gr tac = 2,740fps

privi brass
cci br-4
26 gr tac 2,740fps

privi brass
already primed with privi primer
25.7 tac = 2,740

No signs of excessive pressure on anywhere on cases

The privi brass is not as consitent as the lupua, and in every string there is a flyer, I think because my RCBS electronic scale keeps changing its zero.

23.4-23.5gr TAC behind a 75-77gr mag length bullet seems to shoot pretty accurately. Had to add a light taper crimp to get it to work, though. Started out trying to duplicate some BH 75gr loads, ran up the powder charges and couldn't get anything to shoot worth a dang. Went to pull some bullets from remaining factory rounds - holy *cow* were they in there hard, and only 23.4gr powder - way less than what I was using, but with more velocity and much better accuracy. Reset the powder measure, screwed a Lee taper crimp die down to just kiss, and loaded up a few. Kept adjusting the crimp die a little at a time until I got the load to respond. Yes, I 'know' you don't crimp match bullets (Hornady 75gr BTHP, S77MK, etc.) but I figured sub-moa with iron sights (AR Service Rifle) was 'good enough' for the intended use (200-300yd Offhand and Rapid fire stages).

LC cases
24.5 gr Varget
Hornady 75 gr BTHP
Fed. primers
2.26 OAL

Lake City Cases
26 grains of TAC
62 grain Golden West bullets
WSR primers
3120 fps from 20 inch barrel.

Lapua Brass
25.5 grains of Varget
70 grain Berger bthp
CCI Benchrest primers.
3005 fps from 20 inch barrel

75 gr. Hornady BTHP with 23.8 gr. Varget grouped 1/2" @100. It could have been me or my gun

24.0 gr Varget
23.5 gr TAC

Winchester SR primer
Winchester case
2.245" OAL

With the Varget, I get 2500 fps from a 16" RRA barrel and 2800 fps from a 26" Krieger. That would put a 20" barrel at about 2650 fps but I don't have a 20" barrel with which to test.

The load using TAC is about 100 fps faster from both barrels.

If you want an even better long range load, substitute into the recipe the Sierra 80 gr MatchKing bullet seated 0.010" off your lands. You have to single load them but they do better at extended distances.

RL-15, second choice(s): N140 or Varget

24.0 gn of Varget seems to be the sweet spot for 75-77 gn bullets. Of course that's pretty much close to a max load, so just be careful getting there.

BLC-2, 25.0 grains to be exact with the Hornady 75 grain BTHP Match bullet.

Ramshots 5.56 data for the 77gr bullets show (20" barrel)

Bullet weight: 77 grain HP.
Start load: 22.1 grains (2525 – 2625 Ft/p/sec)
Maximum load: 24.5 grains (2750 – 2850 Ft/p/sec). <62000 Psi

Fired from Sig 556 / 16" barrel (I was going to use my 14.5" Mforgery for this, but I figured that y'all would be more interested in the results from the Sig 556. You're welcome..

23.6gr of TAC
WSR primers
COL 2.255"
75gr Hornady BTHP
FC thrice-fired brass (I live life on the edge, baby..)
Trimmed to min length
Lee Factory Crimp
AVG: 2675 fps

Same load, but switching to Wolf SRMagnum primers
AVG: 2651

I dunno how to figure out Standard Deviation. Temp was ~65 and rainy. Didn't shoot for accuracy; iron sights and a Trijicon Reflex, coupled with steamed up sweaty glasses aren't conducive to a meaningful accuracy test. For velocity reference, TAP FPD supposedly clocks 2528 out of a 16" barrel; TAP 5.56 doing 2713.

No obvious signs of excessive pressure were noted. The WSR primers were predictably showed more deformation than the Wolf Small Rifle Magnum. The latter almost looked unfired, save for the firing pin indentation.

A previous range trip had me using Lake City brass and the old style WSR primers (all other factors being equal). While my chrono was down for maintenance at that time, there was likewise no signs of excessive pressure, either.

When I fig. Std. Deviation I take the highest and lowest out then add the new lowest to the new highest and /2 this will give you the avg. Take your highest - avg. this is your deviation.

Checking out Hodgdons online data, they seem to list 69 grain, and 75 grain bullet weights - although they are NOT Hornady, they do list loads using Benchmark

75 GR. JLK VLD IMR IMR 4007 SSC .224" 2.250" 23.0 2463 39,400 PSI 26.0C 2780 52,300 PSI
75 GR. JLK VLD Hodgdon Varget .224" 2.250" 22.5 2693 40,600 CUP 25.0 2907 48,400 CUP
75 GR. JLK VLD IMR IMR 4320 .224" 2.250" 22.5 2554 39,700 PSI 24.2C 2766 53,200 PSI
75 GR. JLK VLD IMR IMR 4064 .224" 2.250" 21.0 2531 37,500 PSI 24.0C 2827 53,400 PSI
75 GR. JLK VLD Hodgdon BL-C(2) .224" 2.250" 23.0 2646 39,800 CUP 26.0 2858 49,500 CUP
75 GR. JLK VLD IMR IMR 4895 .224" 2.250" 21.2 2506 41,200 PSI 23.8C 2786 51,800 PSI
75 GR. JLK VLD Hodgdon H335 .224" 2.250" 21.0 2624 41,300 CUP 23.0 2814 50,000 CUP
75 GR. JLK VLD Hodgdon H4895 .224" 2.250" 22.5 2696 39,900 CUP 24.5 2905 50,000 CUP
75 GR. JLK VLD IMR IMR 3031 .224" 2.250" 20.0 2543 40,000 PSI 21.8C 2740 53,500 PSI
75 GR. JLK VLD Hodgdon Benchmark .224" 2.250" 21.5 2610 41,900 CUP 23.5 2829 49,400 CUP
75 GR. JLK VLD Hodgdon H322 .224" 2.250" 20.0 2594 40,700 CUP 22.0 2785 48,100 CUP
77 GR. SIE HPBT IMR IMR 4007 SSC .224" 2.260" 22.0 2392 40,000 PSI 25.0C 2672 50,500 PSI
77 GR. SIE HPBT Hodgdon Varget .224" 2.260" 21.0 2528 42,700 CUP 23.7C 2737 50,700 CUP
77 GR. SIE HPBT IMR IMR 4320 .224" 2.260" 20.5 2347 42,000 PSI 23.1C 2654 50,300 PSI
77 GR. SIE HPBT IMR IMR 4064 .224" 2.260" 20.0 2397 42,200 PSI 22.7C 2698 53,000 PSI
77 GR. SIE HPBT Hodgdon BL-C(2) .224" 2.260" 23.0 2640 42,500 CUP 24.9 2804 50,700 CUP
77 GR. SIE HPBT IMR IMR 4895 .224" 2.260" 20.0 2379 41,800 PSI 23.0C 2708 53,100 PSI
77 GR. SIE HPBT Hodgdon H335 .224" 2.260" 21.0 2582 44,400 CUP 22.6 2738 51,700 CUP
77 GR. SIE HPBT Hodgdon H4895 .224" 2.260" 20.0 2474 40,300 CUP 22.6C 2727 50,200 CUP
77 GR. SIE HPBT IMR IMR 3031 .224" 2.260" 18.5 2365 42,200 PSI 21.3C 2692 53,700 PSI
77 GR. SIE HPBT Hodgdon Benchmark .224" 2.260" 20.5 2523 27,400 CUP 22.8 2763 50,000 CUP
77 GR. SIE HPBT Hodgdon H322 .224" 2.260" 20.0 2578 44,900 CUP 21.8 2721 50,900 CUP

I use Benchmark under 75 grain Hornadies.

The 75 grain Hornadies fly best between 2750 and 2800 so adjust your load accordingly.

I use 22.0 grains in my 26 inch Pac Nor on my Remy 700.

I just loaded up some with 23.o grains to shoot over the chrono from the new 20 inch Lothar Walther on the SPR.


I find that TAC is 'freakin' amazing in both 223 and .308. I load it to 5.56 velocities, 26 grains of TAC in Lapua brass driving the Hornady 75 grain bthp is a load that is as good as it can get. :)

I have worked up a few loads in .223 with TAC. It meters perfectly as it is very fine. The load guide Ramshot provides is useless. When I used their info, the velocities I was getting were pitiful. After a bit of digging around on the web, I found some better data. I tried it with both 69 and 77 grain sierras out of a 16" AR with a 1-8 twist. Lake city brass with Wolf primers were used.

With the 69 grain bullet, I ended up using 25.6 grains of TAC for 2760 fps and a .6 moa group. I got the velocity up to 2900 but the accuracy fell off bad. Never had any pressure signs.

The 77 grain sierras ended up giving me quite a few .5 moa groups. I settled on 24.2 grains of TAC for 2570 fps. At 2620 the groups were still under 1 moa but I would rather have a group half that size 50 fps slower. Once again there were never any pressure signs.

I've used Varget and it is good for longer barrels but I've found that Ramshot TAC is a great perfomer, cheaper, meters like water, doesn't compress with max charges and long bullets like extruded, and is temperature insensitive. It has the benefits of an extruded powder with the benefits of ball. It has a good pressure curve for 5.56 and works well for 55 and 62 grain target loads and really good with the 77 grain OTM's. I just wish it got better velocity in the 6.8.

Two weeks ago I loaded 24 grains behind a Sierra 77 grain match King, Lake City brass, Wolf small rifle magnum primers, Lee Crimp and a COAL of 2.260". My M6A3 16" chronographed these loads at 2627 fps. I also shot five of them from my 10.3" M6A1 at 25 yards into half the size of a dime (admittedly not 100 yard testing). The temperature was 23% with windchill, good velocity in cold weather. I e-mailed Ramshot asking them about TAC being temperature sensitive and they responded same day. They tested TAC from -40 to + 140 degrees F. and they had a 3% deviation. That is pretty damn good, especially since I have seen other ball powders change as much as 200 fps between 20 and 95 degrees.

For 10.3 inch barrels H322 is great for 55 - 62 grain bullets.

I have been experimanting with Tac for about a year now and following is some load info I have compiled. The velocities are from my current 1/8 twist
18" 3 land poly rifled bbl. You should crono your load development in your bbl to be sure of your velocities.

Factory (from production lots I pulled and weighed)
BH 68gr Heavy match = 24gr Tac = 2715
BH 75gr BTHP match= 23.8gr Tac = 2700

My Reloads
75gr Hornady = 23.5gr Tac = 2664
75gr Hornady = 24.5gr Tac = ? not chronod yet, but no over presure signs and great accuracy from my bbl.

55gr MG FMJ = 24.2gr Tac = 2911

I load to an OAL of 2.243

I hope this info helps you out. Remember to work up slowly and watch for signs of overpressure

How about 1/2 MOA at 100, 200, and 300 yards with mixed brass, Remington 7 1/2 primers, 75 bthp at 2.255 oal, and anywhere from 24 to 24.5 grains of reloader 15. This out of a krieger tight chambered match rifle with iron sights. It will also work out your loose chambered military style rifle.

Like the 308 in the M1A, loads for the AR .223 are pretty much set in stone. There really is not a lot of load development to be done that hasn't already been done. Thousands of high power competitors use basically the same load. Crimping is not a part of the equation...

Of course, start low and work up. But this is where you end up.

23.5-24.5 Varget or Reloader 15.

Two very accurate loads I've used:
24.5 grains Reloader 15, and 24.0 grains Ramshot TAC (Warning! This one is over the book max!) with Lake City brass and Wolf SR primers. With either powder, start around 23 grains and work up until you get the accuracy you want.

In my 17" MSTN, either of these loads will put ten rounds into 4" at 400 yards, day in and day out.

LC case, =/- .5 grains weighed
CCI BR4 primer
24.3 grains Varget
75 grain Hornady match
OAL 2.250"

2775fps from a 20" Eagle Arms 1X7 barrel, .75 MOA at 200 yards and an SD in the single digits.

Few loads that I have tried out of my 20" inch barrel AR.


62 FMJBT 25.0 wc846 win brass. win srp. ave vel 2742 fps
75 Amax 24.0 wc846 win brass. win srp. ave vel 2528 fps

I load the 77 grn Nosler Custom Comp J-4s (they seem to expand more consistently than Sierras) in Magpul Pmags for the guns that are 1in 8 or faster twist. I load 69 grn Noslers (or Sierras) in Brownells Mil-Spec mags for the 1 in 9 carbines. This way I don’t grab the wrong ammo and can feel what they are in the dark.

I have used Hornady 75 grn at max pressure (for speed) in a 1 in 9 NM RRA 20 inch. This worked in the longer barrel because the higher velocity at the muzzle gave higher rotational velocity as well. I could not get them to stabilize in a 14.5 inch Bushmaster with the 400 or so slower fps.

From the Sierra reloading manual:


VV N140----24.5gr-----2650fps
VV N540----24.9gr-----2650fps

Note: THESE ARE MAX LOADS Proceed with caution.

I checked my notes, and Hornady recommended to me that to duplicate the Factory 75 Gn. FMJBT "Match" load, use 24.0 gns. of WW748 with any quality commercial small rifle primer. I use Winchester primers. This load is a little softer than TAP, but I don't think the BG will notice.


Nosler's website

Bullet: 77gr Nosler Custom Competition HPBT
Ballistic Coefficient: .340
Sectional Density: .219

Primer: ?
Brass: ?
OAL: ?
Trim-to: ?
Barrel: ?
Twist: 1x7

Powder: RL-15
22.5gr - 2487fps (86% density)
23.5gr - 2633fps (89% density)
24.5gr - 2741fps (93% density) <- most accurate out of this 3

Powder: VV N135
20.5gr - 2451fps (78% density) <- most accurate out of this 3
21.5gr - 2555fps (82% density)
22.5gr - 2664fps (86% density)

Powder: Varget
22.5gr - 2466fps (86% density) <- most accurate out of this 3
23.5gr - 2598fps (89% density)
24.5gr - 2693fps (93% density)

Sierra's website

Bullet: 77gr Sierra MatchKing HPBT
Ballistic Coefficient: .362 @ 1800fps+ / .343 @ 1800fps-
Sectional Density: .219

Primer: Rem 7 1/2
Brass: Fed
OAL: 2.260"
Trim-to: 1.750"
Barrel: 20" Colt HBAR
Twist: 1x7

Powder: Ramshot TAC
21.8gr - 2500fps
22.2gr - 2550fps
22.7gr - 2600fps
23.1gr - 2650fps
23.6gr - 2700fps
24.0gr - 2750fps

Powder: RL-15
22.3gr - 2400fps
23.2gr - 2500fps
23.6gr - 2550fps
24.1gr - 2600fps

Powder: VV N540
22.9gr - 2400fps
23.7gr - 2500fps
24.1gr - 2550fps
24.5gr - 2600fps
24.9gr - 2650fps

Powder: VV N140
22.3gr - 2400fps
23.2gr - 2500fps
23.6gr - 2550fps
24.1gr - 2600fps <- most accurate out of all tests (more in the pdf)
24.5gr - 2650fps

Alliant Powder's website

Bullet: 77gr Sierra HPBT
Powder: 24.1gr RL15
Primer: Fed 205M
Brass: Win
OAL: 2.26
Barrel: 24"
Velocity: 2793fps
Pressure: 51200psi

Lapua/Vihtavuori Powder's website

Primer: Small Rifle
Brass: Lapua
Trim-to: 1.752"
Barrel: 25"
Twist: 1x7

Bullet: 75gr Hornady HPBT
OAL: 2.260"
Powder: 23.1gr N540 (min)
Velocity: 2536fps
Powder: 25.8gr N540 (max)
Velocity: 2831fps

Bullet: 80gr Sierra HPBT
OAL: 2.551"
Powder: 21.4gr N540 (min)
Velocity: 2395fps
Powder: 23.7gr N540 (max)
Velocity: 2652fps

Ramshot Powder's website

Bullet: 77gr Nosler HPBT
Primer: Fed 205
OAL: 2.260"
Barrel: 24"
Twist: 1x7 or 1x9

Powder: 21.2gr TAC (min)
Velocity: 2515fps
Powder: 23.5gr TAC (max)
Velocity: 2794fps
Pressure: 52500psi (max)

LOAD DATA FROM INDIVIDUALS - collected from various websites

From ocabj (on calguns):

Bullet: 77gr Nosler CC HPBT
Powder: 24.0gr RL15
Primer: CCI #BR4
Brass: LC

Barrel: 20"
Twist: 1x7
Velocity: 2740fps

Barrel: 18"
Twist: 1x7
Velocity: ~2650fps (unconfirmed, just a wild guess)

Bullet: Sierra Match King 77gr BTHP
Powder: 25.3gr Hodgdon Varget
Primer: Winchester SR Primer
Brass: LC

Barrel: 18" WOA SPR w/ Wylde chamber
Twist: 1x7
Velocity: 2788fps (avg from 5: 2772, 2797, 2793, 2798, 2779)

From thmpr (on calguns):

Bullet: 77 grains Nosler
Powder: 25gr Ramshot TAC
OAL: 2.255" (probably inconsistent OAL, therefore, ES is high)
Barrel: 20" JP CTR-02
Twist: 1x8
Velocity: 2786fps (avg out of 10: 2821, 2786, 2832, 2800, 2799, 2745, 2781, 2776, 2796, 2720)

Powder: 24.8gr Ramshot TAC
Velocity: ?

Bullet: 77 grains Nosler
Powder: 25gr Ramshot TAC
OAL: 2.255"
Barrel: 20" JP CTR-02
Twist: 1x8
Velocity: 2798fps (avg out of 10: 2801, 2793, 2802, 2800, 2799, 2795, 2791, 2804, 2796, 2798)
ES: 13

From billyhill

Bullet: 77 gr Nosler CC HPBT
Powder: 23.7gr Hodgdon Varget
Primer: CCI #BR4
Brass: LC
Brass Trim: ?
OAL: ?
Barrel: 20"
Twist: ?
Velocity: 2786fps
ES: ?
SD: 16fps

From overdriv
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.9gr Alliant RL15
Primer: WSR
Brass: LC
Brass Trim: ?
OAL: 2.255
Barrel: 20"
Twist: ?
Velocity: 2583fps
ES: 69fps
SD: 16fps

From overdriv
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.6gr Ramshot TAC
Primer: WSR
Brass: Remington
Barrel: 20"
Velocity: 2687fps
ES: 30fps
SD: 9fps

From sig685 (exact duplicate of BH 223 Blue Box)
Bullet: 77 gr Sierra MatchKing (Moly) HPBT
Powder: 24.5gr Hodgdon Varget
Primer: Rem 7.5
Brass: LC
Brass Trim: 1.760
OAL: 2.258
Barrel: 24" SS
Twist: ?
Velocity: 2730fps
ES: 51fps
SD: 12fps

From shootsenmeister
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 24.0gr VV N140
Primer: CCI #BR4
Brass: LC
Brass Trim: 1.750
OAL: 2.260
Barrel: 16" SS
Twist: ?
Velocity: 2618fps
ES: 42fps
SD: 16fps

(Extracted from a thread http://www.ar15.com/forums/topic.html?b=1&f=9&t=500036)

From Lawman734
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 25.3gr Hodgdon Varget
Primer: WSR
Brass: LC
Barrel: 18" SPR
Twist: 1x7
Velocity: 2780fps

From Lawman734
Bullet: 77 gr Nosler CC HPBT
Powder: 24gr RL-15
Primer: WSR
Brass: Winchester
Barrel: 18" SPR
Twist: 1x7
Velocity: 2730fps

From Ex0331
Bullet: 77 gr Sierra MatchKing HPBT
Powder: 23.5gr AA2230C
Primer: CCI #400
Brass: LC
OAL: 2.250
Barrel: 20"
Twist: 1x9 (JR: he must be lucky)
Velocity: 2769fps
ES: 24
SD: 17

From Silly_Look
Bullet: 77 gr Nosler HPBT with Cannuelure
Powder: 24.5gr RL-15
Primer: CCI #450 Magnum Primer (JR: I'd rather use #41 Military primer)
Brass: New Winchester
Barrel: 20"
Twist: 1x8 RRA Varmint A4 Heavy Barrel
Velocity: 2662fps
ES: 40
SD: 11


Specification of Mk 262 Mod 1 (non-official source)
http://www.gunsandammomag.com/ammunition/mk262_080105/ (Guns & Ammo article)

Manufacturer: Black Hills Ammunition
Brass: BHA
Bullet: 77gr Sierra MatchKing OTM w/ cannelure
Primer: ? (non-corrosive boxer, crimped)
OAL: ?
Barrel: 18" (Mk12 SPR)
Twist: 1x7
Powder: ? (custom version of Ramshot TAC??)
Velocity: 2783fps

Range: Muzzle (measured @ 12ft/4yds)
Velocity: 2783fps
Path: -2.75" (0" drift from 10mph wind)

Range: 100yds
Velocity: 2534fps
Path: +3.99" (.9" drift from 10mph wind)

Range: 200yds
Velocity: 2299fps
Path: +5.2" (3.8" drift from 10mph wind)

Range: 300yds
Velocity: 2076fps
Path: 0" (9" drift from 10mph wind)

Range: 400yds
Velocity: 1866fps
Path: -13.3" (16.8" drift from 10mph wind)

Range: 500yds
Velocity: 1670fps
Path: -36.7" (27.7" drift from 10mph wind)

Range: 600yds
Velocity: 1438fps
Path: -72.7" (42.3" drift from 10mph wind)

Range: 700yds
Velocity: 1320fps
Path: -124.5" (61.1" drift from 10mph wind)

Range: 800yds
Velocity: 1186fps
Path: -196.2" (84.4" drift from 10mph wind)

Velocity from Various Weapons
(10 rounds @ 12ft/3yds, Oehler 35P chronograph, 30 deg F, 100ft above sea level)
Barrel: 18" (Mk 12 Mod 0)
Velocity: 2783fps

Barrel: 18" (Mk 12 Mod 1)
Velocity: 2791fps

Barrel: 16" (AR carbine)
Velocity: 2751fps

Barrel: 13" (AR carbine)
Velocity: 2534fps

MK262 Velocity data from Novelske (I think..?)

7.5" 2053 FPS ... 10.5" 2363 FPS

10.5" 2363 FPS ... 14.5" 2576 FPS

14.5" 2576 FPS ... 16" 2669 FPS

16" 2669 FPS ... 18" 2769 FPS

18" 2769 FPS ... 20" 2818 FPS


SAAMI Max PSI - 223 Remington 55000psi

6mmBR.com 223 info, great!!

Accurate Powder - 223Rem data

5.56 NATO Specification

Mk262 Mod1 Performance

Great info on Mk262 and other commercial ammo that are like it.

20" White Oak Barrel
1:7 twist
Wylde chamber cut

24.5 grains RE-15
Lake City case
Federal Match primer
75 Hornady BTHP

Awesome load but will flatten primers for me, be careful.

20" Rock River Varminator (predator/varmint hybrid)
1:8 twist
Win brass
OAL standard
AA2520 24.7

69gr bullet (seems not to care about make)
26gr AA2520
my standard load

Lapua Match brass
Federal Match primer
RL-15 23.6 grains
75 grain Hornady A-Max
2.385" coal

Winchester brass
Federal Match primer
RL-15 24 grains
75 grain Hornady BTHP
2.25" coal

Lapua Match brass
CCI BR primer
RL-15 24 grains
75 grain Berger VLD
2.365" coal

20" MSTN SuperSAM Upper 1-8" twist (Lilja 3 groove barrel)
Lapua Brass
Rem 7 1/2 Primers
80 SMK (.015" off lands)
24.6 gr V140

I shoot the identical load with 77gr BT Bergers (loaded to 2.25 OAL) and get 2780fps

Noveske 18" 1:7 poly rifled MK12Mod0

LC Brass, once fired
24.0-24.5gr Ramshot TAC
77gr. Nosler OTM
CCI #41 primers
24.0=2730fps, 24.5= 2780fps

Note- I do not get any pressure signs with 24.5. however, the Noveske 5.56mod0 Match chamber may be looser in the body. Start low and work up. 24.0 yielded a nice dime sized ten shot group at 100 the first time out, but I wanted more velocity within the safe pressure boundary. Also, I do not crimp mine. I believe it can add to the pressure so start low and work up with a crimp if that's your thing.

24 grain TAC 77 SMK COL 2.26

LC 91 virgin brass
80 Berger VLD Moly in the lands
Old lot (96, 97) of N540 25.9, 02 and 03 lot about 26.5 to get sweet spot velocity - 2830 to 2900 in a service rifle
CCI 450 Magnum
Velocity in a service rifle Wylde chamber 2900
Velocity in a 28 inch Wylde built match rifle 3050

Using the match rifle I won the TX state championship 1K iron sight in 97 with the load. Sold the upper to a friend who did not have a good rifle, he won the same match in 98 with it. The load works and very accurate and safe in our rifles. Still shoot the same load.

With .223 reloading for very long range the questions are always:

What twist bbl?
What bullet?
What chamber?

Assuming 80 grainers, they really need a 1 in 7 twist to be reliably stable all the time (like in cool weather).

90 grainers need a 1 in 6.5, which may put you on the limit of how fast you can spin a bullet to make it work.

OAL figures are not useful unless they are chamber specific, and even then are approximate due to throat wear. Jump information, however, can be very useful: VLD's, like Berger and JLK, should be seated to the lands; SMK's don't care that much.

If you get thoroughly confused and want a place to start, take whatever brass you have, load 24.5grs of RE-15 or 24.0 of H4895 behind an 80gr SMK a bit off the lands, and go from there. the load you get should shoot well enough, with low enough SD numbers, to give you a benchmark from which to refine an excellent load. If either of these loads do not work in your rifle, seek help (for your rifle).

In my Derrick Martin standard chamber 22" Douglas 1 in 7 bbl, an 80 SMK seated to the lands with 24.5 of RE 15 gives me 2850fps, and 24.0 of H4895 gave 2875fps and an SD of 6 (!!) last time I chrono'd. Both loads will shoot sub MOA out to 600 plus, stay supersonic at 1000, and are capable of better performance than my skill level can consistently deliver at 1000.

Rem brass

68gr Hornady BTHP
24.3 IMR4895
CCI primers
2.260" COL
2950 fps - measured on a 20" barrel
(need at least 1:8" barrel for this)

69gr SMK
24.7 IMR4895
CCI primers
2.260" COL
2970 fps - measured in a 20" barrel

No signs of over pressure on my rifles, although you better start a 6-8% lower.

Match Load
Lapua Brass
24.5 grains of Varget
Berger 73 grain VLD
BR Primer
no crimp
OA: 2.245

Match load for my son's RR NM
Lapua Brass
24 grains of N 135
BR Primer
Berger Moly 73 grain VLD
No Crimp
OAL 2.245

RRA N/M 20" upper free floated:
25grs Varget
75gr BTHP
MAg Lengh
Win Brass
Win S/R Primer

Rock River 20"1 in 8"Rel-15 24.1grns ,LC-brass cci-br4,75grn horn hpbt,2.250.2780fps-7 shots at 100 .436

Factory Noveske 18"

Die head space setting = -0.0015

Mixed 1x fired cases, swaged, flash holes, and pockets worked - not trimmed.

Powder - RL15

Bullet 77 SMK

Mag Length

Development - 23.8, 24, 24.1, 24.2, 24.4 BHM 75s as a control

Not chronoed.

Things really began to settle out at 24 and above. 24.2 shot as well as BHM 75s. 24.4 - cratered but did not push primers.

LC '04 brass
Rem 7.5 primers
26 grain VV N140
75 grain Amax
Coal: 2.377"
ES= 8
Mv= about 2850

holds about 1 moa @ 1000 yds.
20" WOA 7 twist gas gun barrel

20" 1/9 XCR TACTICAL Remington
LC 07
26.5 RE15
205/450mag/CCI41 all did the same
seated to mag length.

WOA 18" Rifle gas system
1/7 twist
LC 07
24.5 RE15
450 MAG

24gr RL-15
77gr SMK
LC Brass
Federal Match Primers
OAL: 2.260
Trim-to: 1.750
with a 20" barrel and 1x8 twist.
Shoots real good.

Here is what I got this morning through the chrony with temps at 68 degrees:
2710 ......
They continue to be about the same for about 50 rounds...

Out of a 16' RECCE (Noveske polygonal rifled barrel) Chronographed 10' from muzzle with a CED M2.

Avg FPS per 5 shots:
MK262 mod1 (in box).......2732 fps
MK262 (on stripper clips)...2665 fps
24.4gr TAC, LC case, Wolf SR mag primer, 77gr SMK...2698 fps (no pressure signs) accuracy on par with factory MK262

That's my limited experience trying to duplicate the MK 262 load with TAC.

RRA A4 Varmint
20" Wilson 1/8 Wylde chamber
Winchester brass
Fed 205 pr
77 gr. SMK w/ cannetulure
COAL 2.250
23.7 gr. RE-15 or Ramshot TAC
1/2" @ 100yd. 25 degrees F
no chrono data yet, will update

77 gr Sierra MBHP 24.5 RL15 in 20in 1-7 KAC SR-15 Match...no choro data but it is shooting very well at 100 -300 yds. Worked up from 23.5 up to 25 and this shot this best, but all where under 1 MOA (10 shot groups)...best was just over .5.

The Sierra data is a bit low and slow.

The Lyman 49th Edition will give you slightly higher powder charges and speeds but not sure it has all the powders you've listed.

Recommendation for loading GI Mark 262 would be to use a match or benchrest-quality neck sizing die (i.e., Forster S-die) and matching that with a high-energetic (like Vihtavuori 540). You won't be able to match velocity.

Black Hills uses a commercial canister-grade powder you won't be able to buy.

Most match shooters will use either Varget or Reloader-15.

I tried to develop a load similar to Mk262 for my 18" SPR and it was difficult to get one that performed well in the 2700fps range that wasn't too hot. N140 worked best for me.

24.2 gr Varget, Nosler or Sierra 77gr, CCI400 primer in Winchester brass loaded to 2.260 is about as close as I’ve gotten.

I use LC brass/2.255 OAL/210m/75gr Hornys/25.0gr Varget
This load shoot out of my WOA 18" SPR and also my Noveske 16" REECE
18" SPR shoots aprox. 2715 fps
16" REECE runs aprox. 2630 fps

Here's My Mk262 Mod 1 clone recipe:

Firearm: Colt LE6921
Barrel Length: 14.5"
Twist: 1:7"
Bullet: Sierra 77 gr BTHP w/cannalure
Brass: Winchester
Trim-To-Length: 1.750"
Primer: Remington 7 1/2
Powder: H335
Charge: 24 gr
COL: 2.260"
Avg Velocity: 2,629 fps
SD: 6.0
ES: 13.13

NOTE: Velocity was recorded 12' from the barrel, temperature 86 degrees, 175' above sea level.

24 gr Ramshot Tac in LC/ win primer, is really close, 24.5 would get the velocity but experiencing blown primers. When we first started shooting BH ammo then 262 at the navy matches we pulled a lot and tried to reproduce the load. The closest thing we could get was with the TAC powder. 262 is hotter than 77gr smk over counter, if I can find all of my crono data from several years back will post for issued 262 and TAC data.

V-540 will get you the most velocity with a 77, you just have to watch the pressure. I have ran them to 2850 out of a 1/7 Colt 20". The bolt sheared 2 lugs off after about 2k rounds. I backed it off to 2700 after that.

I developed my Mk 262 load back about 2004 when I sat and waited 6+ months for the stuff to become available through Georgia?

Rock River TASC rifle, 16", 1:9 twist. Trijicon TA47-2 2x compact ACOG.

LC brass, 2001 and newer
25.5 gr H4895 (thrown, not measured)
older, WSR nickel plated primers
Hornady 75 bthp match.
2.260" OAL

2740 fps 10' from muzzle. 10-shot, 10" group @ 600 yds in 20 deg temps.

Have put over 500 rounds through without a hiccup. Web expansion does not go over .001"

As many of you may already know, the muzzle velocities that ammunition manufacturers advertise for their ammunition and the muzzle velocities that we actually obtain from our AR-15s are rarely the same. Most often the velocities from our AR-15s will be lower than that advertised by the manufacturers.

For this chronograph session I examined five different loads, from four different manufacturers, that are all topped with the Sierra 77 grain MatchKing.

Atmospheric conditions were recorded on a Kestrel 4000 Pocket Weather Tracker.

Temperature: 78 degrees F
Humidity: 31%
Barometric pressure: 30.08 inHg
Elevation: 950 feet above sea level

The test vehicle for this chronograph session was a Colt AR-15 with a 20” chrome lined, NATO chambered barrel with a 1:7” twist.

Prior to firing the factory loads, I fired a 10-shot string of a control load consisting of one of my hand-loads that is topped with the 77 grain Nosler Custom Competition bullet. This load was previously worked-up in a different 20” Colt barrel to have a nominal velocity of 2800 FPS. The muzzle velocity through this test vehicle barrel was 2803 FPS with a standard deviation of 12 FPS.

The first factory load evaluated was Black Hills’ MK262 seconds. This load had a muzzle velocity of 2796 FPS with a standard deviation of 13 FPS.

Next up was Black Hills’ 77 grain “red box” load. Black Hills states on their website that this load has a velocity of 2750 FPS, but they do not state an associated barrel length with that. From the 20” Colt barrel this load had a muzzle velocity of 2687 FPS with a standard deviation of 16 FPS.

Third on the list was the new COR-BON 77 grain load. COR-BON’s website advertises that this load has a velocity of 2800 FPS from a 20” barrel. I’m here to say “it just ain’t so.” From the 20” Colt barrel it did have a respectable muzzle velocity of 2674 FPS with a standard deviation of 19 FPS. As a big plus, this ammunition comes loaded in Lapua Match brass. You’ll be hard pressed to find a finer brass case to use in hand-loading for the AR-15.

Federal was one of the first manufacturers to offer a factory load using the 77 grain Sierra MatchKing. The information printed on the box of their 77 grain Gold Medal ammunition lists this load as having a velocity of 2750 FPS, but unfortunately it doesn’t list the barrel length either. From the 20” Colt barrel this lot of the Federal load had a muzzle velocity of 2550 FPS. I’ve chronogpraphed an additional six lots of this load over the last several years and the muzzle velocities have ranged from a low of 2522 FPS to a high of 2632 FPS.

Last up, but most definitely not the least is the new 77 grain load from Buffalo Bore. This load is advertised as having a velocity of 2850 FPS from a 20” barrel. I’m here to tell you that this load is smokin’! From my 20” Colt barrel it had a muzzle velocity of TWO THOUSAND EIGHT HUNDRED FIFTY-THREE FPS! This is the hottest 77 grain factory load that I’ve ever chronographed. The standard deviation was 20 FPS.

Hornady lists the velocity of their 75 grain TAP FPD as 2790 FPS (only 10 FPS different than COR-BONS's claim of 2800 FPS.) When fired from one of my 20” Colt barrels with a NATO chamber that load had a muzzle velocity of 2688 FPS, for a difference of 102 FPS less than the claimed velocity. When that same lot of 75 grain TAP FPD was fired from my AR-15 with a 24” Krieger barrel (with a 5.56mm Match chamber) it had a muzzle velocity of 2785 FPS, for a difference of only 5 FPS less than the claimed velocity.

(question) Did you see any signs of primers backing out on the Buffalo Bore load, given that it's so hot and the primers aren't crimped? Were there any other pressure signs with that load?

(answer) The fired primers were as flat as my date to the 7th grade dance, but none were blown, leaking or pierced nor where there any ejector or extractor marks on the case heads. It's an Internet myth that crimped primers somehow magically contain higher mil-spec pressures that non-crimped primers supposedly can't.

I've used once-fired Lake City brass with non-crimped primers to load mil-spec rounds for an additional three firings in a row. Using a Mitutoyo blade micrometer that measures to 0.00005", I measured the case head expansion of the same 10 cases after each of the three firings. The average case head expansion after each of the three firings was only 0.0003" and there were no blown, leaking or pierced primers.

The 77 grain SMK used in the Buffalo Bore load does not have a cannelure. However, the cannelure on the 77 grain SMK used in MK262 is very shallow compared to a typical military cannelure. I have not seen any terminal ballistic tests of the Buffalo Bore load.

Range result:

MK12 Mod 0: 18" Douglas barrel 1:8.

Powder Hogdon H335 22.8, 23.1, 23.4, 23.7, 24.0, 24.2, 24.6, and 24.9. No signs of presure 24.9.

Shot best group at 23.4 (.75moa @ 100yds). Chrono: CED 12ft away.

23-24gr of Ramshot TAC in a LC case with a 77gr SMK is a pretty successful load. I used 23.5gr when I shot an AR in high power competition (1999-2002) in my AR based on a POC at NSWC Crane telling me a little bird had told him that recipe to reload was a good place to start for getting close to Mk262.

I have read of people going as high as 24.5 grains of Tac with the 77 SMK. Work up of course

From my understanding, RL15 is generally the powder used to load the 77 grain match loads for the military shooting teams. It was found too temperature sensitive for use in combat weapons, though.

Though reloaders don't have access to the specific bulk powder that Black Hills uses for its MK262 loadings, many have found success with Tac and Varget. Tac works well in moderate climates, and feeds well through powder measures on progressive presses. If you live where it gets really hot, like AZ, we have to use Varget. Many people have safely achieved or gotten close to MK262 Mod1 velocities with these two powders.

748 burns at a lower temperature than most powders, which reduces heat stress crack formation in the throat, but in .223 I find it wants a heavier bullet to really shine. The 77 grain Sierra MK, for example.

The gunsmith who built my upper uses 23.5 gr. of H4895, CCI primer, and the Hornady 75 gr. bullet as her "proof" load.

I don't know what the speed is, but it's accurate. If I find the test target, I'll post it up.

I personally use 24.5 gr. of RL15, Remington 7.5 primer with the same bullet for my loads out to 300 yards.

in a 1:7 I would go with 75 gr bthp Hornady non molly trim to 1.750 24gr Varget or 23.5gr H4895 COL 2.25 no crimp.

You should be getting about 2600 fps.

I know guys that shoot ground hogs at 600 meters with this load.
Obviously it takes more than 1 shot some times to hit but you get the point.

Just for poops and grins.. I use N-135 for my 600yd loads 25.0gr and a 80gr SMK I get an average of 2810fps. I only use the 69's for 200 and 300yds and 24.0gr Varget

People say that Blackhills .223/5.56 is loaded using TAC. Not sure if that's true.
It's my powder of choice for .223

I've used Alliant Reloder 15 and either Rem 7 1/2 or Fed 205M primers on thousands of rounds for Highpower.

My short line load (200/300 yds) was 24.7 gr on Re15 under a Hornady 75 BTHP.

My 500/600 yd load started with the same load except I loaded a Hornady 75 Amax. Later on I switched to Berger 80 VLDs and reduced the charge to 24.5. The 75 Amax was .01" off the lands, the Berger was jammed .02".

These loads are commonplace in Highpower and completely safe in in my rifle and in the majority of 20" Wylde chambered rifles, which dominate Service Rifle competition.

I would not have any concerns at all in loading up 24 to 24.5 gr of Reloder 15 and Hornady 75s for carbine use.