New Barrel Break-In Procedure

I’ve put off writing about this subject because there’s a ton of theories out there that all fly in different directions, and people get very touchy about their methods. So what I’m going to do is tell you what works for me. Do not consider this gospel, follow my guidelines at your own risk, etc.

Also, you’ll see instructions below to “clean.” Now, when I say “clean,” I don’t mean beat the crap out of the bore with a wire brush – I mean use a good, appropriate solvent, a bore guide, a one-piece coated rod (Bore Tech, Dewey, or Tipton CF), flannel patches and a nylon brush. I like Bore Tech cleaning products (Eliminator for centerfire and Rimfire Blend for rimfires), but many other solvents out there will equal Bore Tech’s.

When I clean a barrel with Eliminator or RfB, Bore Tech’s instructions work quite well: a few wet patches, brush, a few more wet patches, soak, then dry patches until they come out clean.

That said, I basically have two different procedures for basically two different types of barrels: factory production and custom hand-lapped.  We’ll start with the latter, because it’s really easy.

When you get a new firearm that has a custom hand-lapped barrel (like Krieger, WOA, Hart, Lilja, etc.), most of the work is done for you already. All there really is to do is some minor break-in, and that process is simple:

  1. Clean
  2. Fire one shot, clean (repeat 3 times)
  3. Fire three shots, clean
  4. Fire five shots, clean

And you’re done.

Now, with a factory barrel, you’ll find that the throat will be quite a bit rougher than a hand-lapped barrel. My procedure for a factory barrel is similar to the above, albeit a longer process, and I also incorporate an abrasive cleaner like JB bore paste. This is the procedure I use on my Rock River and other AR-15’s, Sig 556, Savage rifles… basically any rifle without a high-end lapped barrel.

Break-in procedure for factory barrels:

  1. Clean.
  2. Work the first 4-5 inches of barrel from breech with a small amount of JB bore paste on a patch, back and forth 10-15 times.
  3. Repeat steps 1 and 2 two more times.
  4. Clean.
  5. Fire one shot, clean. (repeat 5 times for SS barrel, 10-15 times for Chrome-Moly barrels)
  6. Fire three shots, clean. (repeat 3 times for Chrome barrel)
  7. Fire five shots, clean.

Now repeat that whole process until copper fouling is minimized – usually about 3 times on a centerfire rifle, 5 times on a rimfire rifle.

Tedious, isn’t it?

There is an alternative that works quite well: fire-lapping kits. These are just bullets with abrasive coatings that polish the throat and bore. I like Tubb’s Final Finish system. I won’t go into how to use it – just follow the his instructions… it works wonders.

As always with these kinds of things, your results may vary, try at your own risk, etc., etc.

Here are some other handy references if you want to learn more about the barrel manufacturing process and break-in – you should listen closer to the recommendations from the manufacturer of your barrel than me:
Krieger process
Lija process
Hart recommendations (see, they say no abrasives and no break-in necessary!)
Tubb’s fire-lapping info

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