Hand Lapping Barrels

Procedure for hand lapping a barrel for improved accuracy

New barrels (factory variety, not custom made) come with very small imperfections in the rifling cuts. The small imperfections are like microscopic burrs, if you will, that literally tear the copper from the jacket as the bullet passes over them. Custom barrels are hand lapped before they are shipped, and so these imperfections have been removed. The Tubbs system uses grit impregnated bullets that you load yourself and shoot them normally. The grit grinds away these imperfections as the bullet goes down the barrel. The trouble is, some say too much is ground away, especially in the throat area of the barrel. Hand lapping does the same thing except it requires considerably more "elbow grease". I use a jag that is 1 size smaller than the barrel I am working with so that limited pressure is brought to bear on the barrel. I load up a patch with #800 lapping compound, and run it through the barrel back and forth for about 200 strokes (changing the patch and reloading it with compound every 50 strokes). Then I clean the barrel thoroughly with Kroil and Break Free to remove any remaining grit from the compound. Then I dry patch the barrel about 3-4 times. Then I start all over again, except this time I run the patch in one direction only (down) for about 200 laps, this time changing the patch after every 10 laps. After that I go the Kroil, Break Free, and dry patch route described above until the patch comes out clean. Next I load a patch (regular size jag this time) with Flitz metal polish and run that through 15-20 times, and clean the barrel again as above. I finish with a light coating of KG-2 gun oil for storage.

That's about it. It seems like a long process, but it really doesn't take all that much time. I do this to every new barrel I get. I can't say that accuracy is improved significantly, although I believe it is, but the barrel doesn't foul as quickly allowing me to shoot more shots between cleaning.

This same process occurs over time as you shoot the gun, but it does take a quite a few shots. Now for the "other" schools of thought for you to ponder:

1) Some folks say "Just break in the barrel normally and don't worry about lapping."
2) Some folks say "Lapping is a waste of time because it doesn't really do any good."
3) Some say "Get 'ur done quick with Tubbs." (Of course that is a bit tricky if you don't hand load)
4) Still others say "Just take it out of the box and start shooting."

When I'm out shooting, I don't clean the barrel every 5-10 shots unless I'm testing a particular load variation or other equipment/situation. The little bit of copper you refer to is (was) constant in my model 110 that is 15 years old. I lapped the barrel a few years ago and now copper fouling is minimal and clean-up is a snap. Used to be the darned thing would be full of copper after only a few shots. The gun had probably been shot 500-600 times prior to my lapping the barrel and the barrel still copper fouled every time out. After I lapped it, I can shoot it 30-40 times and I don't see any copper in the muzzle. Was it the lapping or just shooting it 500-600 times? Either way, it doesn't foul now. The change was so sudden, though, it had to be the lapping. I have a 7MM mag Savage that doesn't show any sign of copper even after 20-30 shots. It is practically new (less than 50 shots) and the barrel was lapped before the first shot (as all my barrels are now). I used to be a "number 4" too, but since I decided to start lapping my barrels, clean up takes on a whole new dimension. I'm sold on it.