Subsonic 223 loads

Subsonic and reduced 223 reloads – with discussion on effectiveness and focus on use with suppressors

(Probably a little dated as it does not mention ballistic tip bullets. Also includes some Hornet information too)

Subsonic .223 rounds are available, but they offer little over the .22 rimfire. Pricing for subsonic and high velocity ammunition that deforms substantially on striking tissue is greater, as the bullets for these rounds are custom built. If accuracy is a problem with a slow twist, simply turn the bullets around and shoot them backwards. They will print better and do more damage upon striking. The 98-grain .223 bullets need a 7" twist in order to stabilize, and WILL NOT WORK with a 12" twist. Subsonic rounds that will not cycle the M16 action are fairly common. They are available from a number of suppliers at reasonable cost. They are also easy to build for the home reloader. Since they use less than 5 grains of propellant, they tend to be very quiet in a suppressed firearm. Don’t waste your money on a self-cycling .223 round if you are shooting a bolt-action or another manually cycled weapon – like the newer pump and bolt-action AR15 uppers that are coming out on the market lately.

IF YOU REALLY NEED SUBSONIC .223 THAT WILL BE EFFECTIVE ON LIVE ANIMALS, ANOTHER OPTION IS TO CAST AND LOAD YOUR OWN BULLETS. Flat-nosed bullets with flat bases (a true cylinder) are most effective. The African hunters of old used solid bullets with noses shaped like a hemisphere (ball end), and these were the most stable of all the possible shapes. Regardless of what they hit on the way through, they continued on a straight and very deep path. There is a big difference between high-speed, supersonic bullets, and low-speed, subsonic bullets. Supersonic bullets should be sharply pointed, with a smooth, streamlined shape that will slip easily through the air because the frictional drag on supersonic bullets is roughly four times that which pulls on a subsonic bullet. It takes a lot of energy to break the sound barrier on a continuous basis. A properly constructed supersonic bullet moving at Mach 3 or 4 has the power, speed and centrifugal energy to easily upset on contact with a live target, expanding and delivering most of its energy in the process. A subsonic bullet will not expand to a significant extent; thus it should have a shape that will do the most damage before it leaves the barrel. Dr. Fackler's experimentation tells us that this most effective shape will be a flat nose. When someone pulls together an intensive body of research that leads to an obvious conclusion, we believe them. With regard to a flat nosed bullet, drive a piece of 1/2" diameter water pipe through a wooden two-by-four with a hammer, and you'll see what we are getting at with regard to damage resulting from such a shape. Our research tells us that the most effective bullets will have flat noses and bases, with just enough roundness on the front and rear corners to allow them to be shoved into cases and fed into chambers. A soft lead bullet deforms upon entering flesh and tends to be effective at relatively close range. A sharply pointed bullet does not make for effective subsonic animal control unless it has its tip filed to a 45 degree angle, so it will dive and go sideways like a spoon nose. Jacketed bullets are usually more accurate than cast bullets.

Some of the accuracy increase or decrease with subsonic bullets has to do with the way a powder charge obturates or mashes the base of a bullet forward. If the base is not flat the sides will not be supported by the barrel, and will often mash crooked. Indeed, if the forward part of the lead core is too thin and not supported by the bullet jacket it too will flatten out under supersonic acceleration forces during the first inch or two of travel. Think of the core as being made of Jello and it will be easier to understand. Some of our preference for a simple flat base has to do with the secondary step that must be taken when the so-called boat tail is added. A taper on the back of a bullet is rarely put on perfectly straight. Putting that rebate on the back changes the front of the bullet. The boat tail is a fancied attempt to make a bullet tapered in the back like a displacement (slow) boat, or the tail of an airplane. In military FMJ bullets the boat tail is a feature that aids instability and helps the projectile to do a 180-degree flip on the way through tissue, causing more damage without violating the wording of the Geneva Accord. Bullets are not the same as boats or airplanes. Boats & planes are self-powered, and (hopefully) self-correcting. Bullets get only one power impulse to get and keep them moving, are not-self correcting, and extreme accuracy is important. It is easier to make and shoot an accurate bullet if it has a flat base. The bottom line is that the benchrest people tell us that flat-based bullets tend to be more accurate because they are more uniform when they leave the barrel. Flat-based bullets are also more accurate because the square base tends to leave or break with the crown of the barrel more cleanly, unlike a tapered base which is more easily pushed to one side or the other as a bullet exits a barrel. Finally, the flat base tends to remain stable in flight because the wider base touches the air stream on a continual basis, further stabilizing the bullet.

A .223 barrel with a fast 1 in 7" twist may be capable of stabilizing a hard-cast Linotype bullet as heavy as 100-grains, at 950 fps. A heavy bullet with a deep hollow in the base has for years proven stable at subsonic velocities. All cast Linotype bullets should be tumbled in moly for 10 minutes. They should then be stood on end and given a light sealing coat of Hornady One-Shot, spray case lube on both sides. Don't use gas checks, as they sometimes fall off inside suppressors, and are tough to shake out. One is best off using a bullet with minimal grooving and only moly and One-Shot for lubricants. Melt and cast the lead out of doors to avoid getting lead poisoning from fumes. Stay with the harder Linotype alloy instead of pure lead, which is normally too soft. Seat blunt-nosed bullets deeply, so the shells feed and chamber easily from the magazines. Magma makes bullet-casting machines and molds for those who require high production.

For a JACKETED, SUBSONIC ROUND in suppressed weapons we like Speer's 70-grain semi-spitzer, soft point, as it comes closest to a round-nose, flat-base. We have seen lead-cored bullets as heavy as 100 grains, and tungsten and uranium bullets as heavy as 150 grains. These are not yet available as loaded rounds, and the U.S. is currently unhappy with uranium rounds in the hands of civilians. Loaded, subsonic .223 ammunition is currently available from Black Hills. The point of impact (POI) of subsonic rounds will be different from supersonic rounds (usually much lower and a bit left) because of different recoil characteristics. Some who use both rounds in the same weapon use an optical sight for high-powered ammunition, while the weapon's iron sights are adjusted just for subsonic rounds. While expanding the versatility of the weapon, this concept could spell disaster in a court of law if a shooting ever went sour. Another technique is to use the lower part of the vertical part of a duplex crosshair as the aiming point for subsonic ammunition. Extensive practice is recommended to achieve familiarity with both types of ammunition. Aguila currently distributes a .22 LR round that weighs 60-grains. These do not work very well in M16s that have been temporarily modified with a sub-caliber conversion kit. They often jam, and a single round loudly burps its gas out the breech because the shell is very short. Subsonic 40-grain ammunition works in the conversion kit, but the kits have to be kept clean and well oiled for any sort of reliability. Subsonic ammunition delivers a small fraction of the energy to the target, but the sound level from a suppressed weapon is virtually undetectable. Teams should practice with the rounds they have chosen, both on paper and on hard and simulated soft targets. Coconuts, tomatoes, cabbages and water-filled jugs are interesting, and they provide the shooter with useful simulation of what he or she can expect in the field in real life.

Misc posts on forums regarding subsonic 223 loads

(with some data on Hornet mixed in)

I have used 700X for reduced loads in .22 Hornet, .222 & .223. They were all fired in bolt guns. I seriously doubt they would cycle an AR.

You can achieve about 22 hornet levels, with just about any bullet weight.

It's not for the beginner, but minimum of about 4 grains and work up to your desired velocity.


Thanks to Seafire's pioneering work in the area, I've found Blue Dot to be an outstanding and consistent powder in .223 for slightly reduced loads. I settled on 13.5 grains with a 50 grain jacketed bullet for 2850 fps in my gun. You can go slightly higher, but what's the point? It also works well in my Hornet and K-Hornet at about 200 fps below "full power" loads.


This will keep you both busy and also out of trouble.. just always remember to work up...

Blue Dot Range Report: 223 Caliber ( Full )

Bullet Weights Tested:

35 grain Hornady V Max
2. 40 grain Hornady Vmax
3. 45 grain Sierra SP
4. 50 grain Sierra SMP
5. 52 grain Sierra Boat Tail Match
6. 55 grain Winchester FMJ

Rifle Used: Ruger 77 Mk 2, VT 26 inch Barrel, Stainless Steel First yr Model

Case: Lake City Surplus, previously fired

Primer: Remington 6 ½

Powder: Blue Dot

Charge Weight Tested: 4 grains to 14 grains.

Weather: Sunny, NO clouds, 80 degrees, NO wind,

Altitude: 2000 ft

Humidity: Very Low

Field Results:

35 grain Hornady V Max:

4 grs: 1284 fps
5 grs: 1488 fps
6 grs: 1862 fps
7 grs: 2163 fps
8 grs: 2392 fps

9 grs: 2636 fps
10 grs: 2722 fps
11 grs: 3076 fps
12 grs: 3205 fps
13 grs: NO Reading
14 grs: 3518 fps

15 grs: NO Reading, Too hot, Extractor Marks, Scrapped Case
16 grs: NO Reading, Too Hot Blew Primer

Hornady 40 grain Vmax:

4 grs: 1161 fps
5 grs: 1538 fps
6 grs: 1798 fps
7 grs: 2148 fps

8 grs: 2243 fps
9 grs: 2539 fps
10 grs: 2771 fps
11 grs: 2956 fps

12 grs: 3013 fps
13 grs: 3218 fps
14 grs: 3375 fps

Sierra 45 grain SP

4 grs: 1239 fps
5 grs: 1447 fps
6 grs: 1688 fps
7 grs: 1880 fps

8 grs: 2118 fps
9 grs: 2363 fps
10 grs: 2553 fps
11 grs: 2811 fps

12 grs: 2875 fps
13 grs: 3008 fps
14 grs: 3164 fps

Sierra 50 grains SMP

4 grs: 1064 fps
5 grs: 1345 fps
6 grs: 1624 fps
7 grs: 1788 fps

8 grs: 2033 fps
9 grs: 2257 fps
10 grs: 2466 fps
11 grs: 2655 fps
12 grs: 2779 fps

13 grs: 2882 fps
14 grs: 3038 fps

Sierra 52 grain Boattail Hollow Point Match

4 grs: 1061 fps
5grs: 1460 fps
6 grs: 1632 fps
7 grs: 1916 fps

8 grs: 2142 fps
9 grs: 2225 fps
10 gr: NO Reading
11 grs: 2673 fps

12 grs: 2782 fps
13 grs: 2879 fps
14 grs: 3012 fps

Winchester 55 grain FMJ

4 grs: 896 fps
5 grs: 1264 fps
6 grs: 1568 fps
7 grs: 1825 fps
8 grs: 1994 fps

9 grs: 2201 fps
10 grs: 2328 fps
11 grs: 2453 fps

12 grs: 2677 fps
13 grs: 2821 fps
14 grs: 2915 fps


1. In the evaluation of the 223, I came further to the conclusion of the versatility of the 223 in the use of training new shooters, and for a very versatile varmint caliber.

2. Essentially the 223 can be loaded to the specs of a 22 Long rifle, a 218 Bee, a 221 Fireball, a 222 Remington, a 22 Hornet, and a 22 Win Mag., while allowing the shooter to be able to pick the type of bullet that he prefers.

3. Bullets were limited to use of 35 grains to 55 grains. Heavier bullets will not serve any purpose unless a 223 is to be used for deer hunting. I do not believe that there would be a significant difference in the use of a 55 grain bullet vs a 60 grain bullet.

4. The recoil on the lighter loads using 4 to 6 grains of powder had minimal recoil if any at all. These would be ideal for young shooters being trained.

5. Noise level on the lighter loads ( 4 to 6 grains) were on par with a rim fire. An increase in noise level was very noticeable above 7 grains, but still very acceptable. (Not sounding like a rim fire any more)

Noted Observations:

1. It was noted but not considered part of the testing, with a tree used as a back stop for some of the testing, that all bullets ( 45 to 55 grains)penetrated thru the tree at a distance of 20 yds.

2. The diameter of the tree was measured at 5 inches.

3. The 40 grain Vmax loads failed to penetrate the tree at loads above 10 grs, above 2771 fps. However at 10 grains and less, the bullets penetrated thru the tree and did a large amount of damage (like turning the wood into tooth picks) on the exit side of the tree. The penetration stopped at the 5 grain load.

Some of the Author’s Conclusions:

1. I learned some significant items beyond the versatility of the 223 with the bullets tested, but focusing on its use in the field, got some ideas.

2. A light rifle such as a Winchester Featherweight or Rugers Compact model with a 16.5 inch barrel or the Ultra Light with a 20 inch barrel would make a good combo with the use of Blue Dot.

3. Since the powder is burned cleanly in the first 10 to 12 inches of barrel, the shorter barrels are not handicappiing velocity in the lighter shorter rifles.

4. The penetration of the 40 grain Vmax into the tree did make me ponder the use of those plastic tip varmint rounds as potential loads for small deer for youth shooters. Just like my observations in the larger calibers, the plastic tipped bullet seem to do a lot more damage, at velocities under 2700 fps. The Vmax surprised me. This is a decision any shooter will have to test on his own and make their own decisions. I am just passing on that I saw potential merit in the application.

60, 63, 64, 65 grain bullets and then the larger match bullets did not give what I considered useful velocity when I have shot them before with Blue Dot, in respect to their field design uses.

Seafire (reported expert on light 223 loadings)

My target load for the .222 Remington is 11 grain Blue Dot, bullet weight 50/52 grain. Precision is as good as with full N133 loads, lead required for shooting the running boar is a little longer. No pressure signs at all, little report/heating/recoil, too.


18 gr Blue Dot 33 gr Vmax 2.17 jammed into the lands is 4100 fps with no pressure sign half the time and 4200 fps with bad pressure sign the other half the shots.

Don't do that.

3600 fps is the speed limit for heavy shooting and avoiding bore cleaning.

15 gr Blue Dot 33 gr Vmax is 3600 fps and low pressure.

It burns clean and the barrel does not get warm, so I can shoot 500 rounds without cleaning or waiting to cool down, and still have moa accuracy.

My notes from yesterday in a rifle that I had never shot before:

Ruger #1, .223 Remington varmint model.

6.5x20x40 Leupold vari-iii boosted to 13x40x40

I cleaned the bore with Butch's Bore shine, Foul Out, more Butch's, ect, until I could see no copper and then I burnished it with Lyman Moly bore cream.

b) 15 gr Blue Dot 33 gr Vmax moly, 2.170" OAL does not reach lands,
a) a fouling shot an inch low and I corrected
b) 0.4" 3 shot group @ 50yards
c) 0.92" 5shot group @ 100yards
d) 0.46" 5shot group @ 100yards
e) 0.9" 5shot group @ 100yards
f) 1.02" 5shot group @ 100yards
g) 0.61" 5shot group @ 100yards
h) 0.75" 5shot group @ 100yards
i) 0.3" 5 shot group @ 50yards

That is an average of .78" 5 shot @100 yards. I knew the gusty wind was driving the group size, so I did the last group at 50 yards.

I have hundreds of rounds of that ammo already loaded, but I need to try bullets seated further out for that rifle.

I learned about Blue Dot from Seafire here on AR and I think he learned it from Calhoon.

Thousands of rounds and 12# of Blue Dot later, I am grateful to both of them.


That 35 grain bullet sucks! It is not very aerodynamic at all... Move up to the 40 grain V Max, and life takes a whole different perspective...Sierra's 40 grain HP is also another great choice, and more economical!

Calhoon's 37 grain HP is also a great bullet for what you are looking for!


I'll second the 35gr; I had thought they'd be okay at the lower velocities, but no such luck.


I really want to thank seafire for sharing his data. I used it to work up loads for my Colt HBAR A3 Precision AR rig. While none of the loads will cycle the action, that is fine with me. I was actually very shocked to find that the subsonic and reduced 50 grain loadings gave better accuracy out of my 1 in 7 twist barrel than I was expecting. I was getting 1.5 and 1.25 inch groups which I find acceptable for what I plan on using them for. The report is almost non existent and there is no flash with the naked eye in the dark. I even worked up a 62 grain load which is very accurate.


Subsonic 223--

55gr flat base SP
3.0 - 4.0gr UNIQUE, depends on barrel and local environment
LC brass, WSR primer

Follow all prudent safety measures. These loads appear stable in 1:7.7 and 1:9 barrels.

I've found some references on the web through Google which refer to using faster powders for the 50-55gr bullets, such as Clays, N310, etc, but haven't tried any.

Zak smith

I just got back from the range and I thought I'd share my experience with subsonic 223.

I loaded HP38 in Winchester cases with CCI primers and Winchester 55gr projectiles. I chrono'd them at about 15 feet. Rifle was an AR-15 with a 16" barrel 1/9 twist.

HP38 4.0 grains, four rounds fired
1246 fps
1230 fps
1231 fps
1229 fps
No problems, but not quite subsonic

HP38 3.5 grains, 4 rounds fired
1100 fps
1066 fps
1042 fps
1110 fps

The 3.5 grain load grouped about half an inch (6 rounds at 15 yards offhand), no keyholes

The rifle did not explode, and, obviously, did not cycle. Primers showed no signs of overpressure.

(new member)

I tested some of these loads yesterday:

-Milsurp brass
-4.5gr of Unique, and 4.0 gr. of Unique
-53gr Sierra Match Hollowpoint bullet (I had a half-box of these I wanted to use up)
-CCI Small Rifle Magnum primer

Velocity with 4.5gr of Unique averaged 1340fps
Velocity with 4.0gr of Unique averaged 1140fps

Test rifle was an NEF Ultra-Varmit with 24" bull barrel.

Good news:
-No bullets stuck in the bore! As you can see, velocity was satisfactory.
-Accuracy was very good. I shot only at 30 yards (in the desert, plinking). Both loads shot into nearly the same hole at 30 yards.

Bad news: POI was about 4" below POA. I suppose I should've expected that, going with the scope zeroed for a 3,200 fps load at 100 yards vs shooting at 1,100 fps at 30 yards. I was hoping to find a range where POI and POA matched, with my existing zero. I didn't have enough time to check other distances. But starting 4" low at 30 yards, I don't think the bullet was still "climbing", so I doubt I'll find a good distance where I can use the existing zero.

Noise was about the same as a .22 LR.

So, I essentially created a .22LR out of my .223. Now that I've done it, I don't see a use...

Dave R

I tried three for 55g fmj bullets:

Alliant offers a max load of 14.0 grains of 2400, at a velocity of 2,685 fps. But that's more than twice the speed of sound, so it's not subsonic. That load would not cycle any of my AR-15 rifles or carbines. Just not enough gas to unlock the bolt and move the carrier. I even went up to 14.5 grains and it didn't move the bolt one bit.

Hodgdon offers a load of 3.1 grains Titegroup at 1,064 fps, and another load of 3.2 grains Clays at 1,060 fps. Both are below the speed of sound and feel like shooting a 22 short. But neither one came close to cycling the bolt. The bolt didn't even budge one tiny bit.


55gr Prvi FMJBT
3.1gr Titegroup, Check hodgdon's site for accurate details, such as OAL as I can’t remember it.

What I do remember:

20" AR, doesn’t cycle the action (have a good charging handle, when fired, you hear the bolt rotate a little then click back forward), about at quiet as the Aguila 60gr SSS (shot them with no hearing on and didnt have ANY discomfort) however with slightly higher velocity (I got 1015 on my Chrono as the fastest). All rounds left the barrel. About a 2" group at 50 yards (irons). They shoot low at closer range due to, well, an AR's higher sights.

Awesome fun round, very quiet, cheap to make (relative to factory cold loaded munitions), fun like a gallery load! The neat thing is with my 1/9 twist barrel, there are no accuracy issues as with a .22 conversion kit as the twist rate is good for bullet weight (unlike the lighter stuff). I will keep 20 of these with blue marker on the head stamp in my SHTF bag as a squirrel/rabbit load.

What I want to try next is to see how different bullets will act. Maybe I can get a Vmax to expand rather than fragment, then I may be onto something. I love the idea of "cat's sneeze" loads and will be trying it with reversed boat tailed heavy bullets and Unique for 7.62x54R.


I've been doing some searching on here and google and found out a few things...

1. Most light loads for .223 involve small charges of pistol powder.
2. Longer bullets tumble at low velocities.
3. Going too slow increases risk of stuck bullets.
4. Copper jackets increase risk of stuck bullets.

I've seen certain AR-15 kits online that allow you to fire 22LR through an AR upper. Then I got to thinking... would it be possible to use unjacketed 22LR bullets in a .223 case? Since the bullet is unjacketed and .004 smaller than a .224 bullet, I'm thinking the risk of a stuck bullet would be much smaller than trying to push a .224 out with a light charge. Should I start with a squib load to see what happens?



22 LR are heeled bullets. The smaller diameter may not obturate enough to seal the bore and stabilize the bullet. Some people roll the pulled 22 around to make round shot.

Lead bullets slide down the bore and yield higher velocities. Jacket bullets are a little more sticky.

In short, yes it should work. In actuality, sounds like a lot of work. Buy a bucket of cast and try it. Someone may even trade you for a handful.

There are several sites that deal with this.


I have used Hodgdon's recommendation of 3.1gr Titegroup and a 55gr FMJ bullet. It's more than fast enough in the 1000fps range not to get stuck...and its subsonic out of my 20" 1:9 AR. I haven't shot it for accuracy yet.


came across these from Accurrate.

It says they were developed for a 223 Rem chamber and are OK in a 5.56 chamber. Rem case and 7.5 primer with Accurrate S-1250 powder. All loads chronographed in a 24" barrel. Subsonic loads will not cycle an AR-15.

IMI 55gr FMJ 3.5gr S 1250, COAL 2.230, 1139 FPS for 13,500 PSI

Hornady 60gr SP 4.2gr S 1250, COAL 2.235, 1111 FPS for 19,100 PSI

Hornady 75gr HPBT 4.5gr S-1250, COAL 2.255, 1052 FPS for 22,100 PSI

Refer to Accuate Powders web site for any questions since I haven't tried these.

Here is what works for me. 55gr flat base bullet (Speer-Sierra-etc.) TrailBoss powder; approx.3.5 to 3.8grs of powder. you may want to start at 4.0grs and work down to the 3.8gr load. TrailBoss nicely fills the brass almost half way. That helps to keep ignition consistent. Standard small rifle primers work fine. Do not go under the 3.5gr load as there is a fine line between subsonic quiet and BULLET STUCK IN BARREL! In my m-16 with HALO suppressor the loudest sounds are hammer impact and bullet impact.

I looked on the Hogden site and found a subsonic load: 3.1 grains of Titegroup and a 55 grain bullet. I tried 3.1 grains of Titegroup under a Nosler 69. It works, doesn’t cycle the rifle but its quiet. The gun kind of rattles a bit when it goes off. Kind of a beefed up .22lr. About six inches under the zero for my normal ammo.

As he said, a problem is that a subsonic 55 grain has about the same muzzle energy as a High velocity .22 Long Rifle. On the other hand a heavy 77 grain bullet will not give great accuracy unless the correct barrel twist is used. The Shooting Times says a 1:8 twist rate is the minimum need to stabilize a 77 grain Sierra MatchKing.

Blue dot is one of my favorite powders for 223 bolt actions but may not cycle an auto. You need to go very slow and careful load blue dot, It may be reduced velocity but not low pressure. How reduced are you looking to go?
I load mine down to Hornet velocity but you can run it down to 22 mag vel.
I’ve loaded it in 40, 45, 50 and 55gr hornady with great accuracy and consistency. I’m getting1/2"groups@100yds with 40gr v-max.