bigcountry

This is prime example. I just got a new Mod 70. Barrel is very rough. Showed promise on the first 20 shots. I am impatient. I want to start load development now, not later. I do a regular breakin, and velocity spreads are going down but very slowly. I take a little JB's. Actually alot, 300 strokes. Velocity spreads of a130gr Sierra Bt went from 100fps, to 50fps on the second round of shooting. Sure you can shoot the gun, and do the same thing, but I wanted to speed things up a tad by breaking in. Now with 54gr of 4350 270win, I get .8" groups if I let it cool down 8 min between shots.

polack

Had two guns built by a local smithy and he recommended, first shot-clean, second shot-clean, third shot-clean, and then go to town. This seemed to work very well on these particular rifles.
Polack

westbronco

The main reason you break in a new barrel is to make it easier to clean. If there is any improvement in accuracy, it's nearly impossible to measure. That said, if you are talking about hunting rifles that get cleaned a couple of times a year, it's not worth it to break them in.

On the other hand, if you have varmint rifles that might get cleaned ten times in an afternoon's shooting, it is worth doing. You can break in any barrel at any time as you are just smoothing out any tiny rough spots remaining in the barrel by shooting thru the totally clean barrel. The point of complete cleaning before the next shot is to expose the ultra tiny burrs to the next bullet. If there is copper in front of the burr, the bullet will not scrape off the burr, but will just pile up more copper.

You can tell that you have completed the break in when the barrel begins to clean up very easily. That absolutely cannot be predicted for any given number of shots. A top quality barrel such as a Shilen may take five or ten while a typical factory barrel could take a few dozen. Bottom line is, the barrel is broken in when it's broken in. Only the shooter can decide if it's worth the effort.

James B

All I do is to clean the heck out of my new barrels about every ten rounds until I get to a couple hunders rounds. This has worked well for me. Don't know if it the best way or not. I quess if it ain't broke I won't try to fix it.

Nomercy

I tend to believe that BBL break in is bull, even on mass produced bbls I don't believe you're honestly going to help your accuracy much by doing it....BUT, I do it still, better I do everything I can to help my accuracy, even if it doesn't help, at least I did it if it would have. Kinda like not being superstitious, then having a bad day on Friday the 13th, worrying about breaking mirros, or not walking under ladders.

There are going to be a million different ways that people will tell you do do this, basically none of them are right, and none are wrong.

Breaking in a bbl basically consists of filling "pits" with copper and smoothing the grains of metal in the bbl, getting everything to line up the right way (that's why you're never supposed to run patches through muzzle to action too, so you don't alter this at all)

Lots of varminters and target shooters swear you should use some sort of polishing compound in your bbl to help smooth things out, I'd tend to agree with that, but I'd fire a box or so before adding the polishing compound, to kind of get things going so to speak, get things pointed the right way, then smooth it out.

My method is usually run 5rnds through cleaning to CLEAN after each one, then run 3shot groups for 3-4groups cleaning after each one (fire them fast enough for the bbl to get warm, not hot though), then I go to cold grouping at 3 shots each, running a solvent patch and an oil patch through each time.

Pretty much the only thing I honestly feel break-ins do is get things shooting to their potential faster, run enough rounds through your gun and it's going to get to the same point after a while, it just speeds things up to give exposure a raw bbl for a while.

Nomercy

Truth be told, the real effect of bbl break in likely has more to do with the fact that you're running a lot of rounds through your bbl before you consider it "done and ready", rather than starting out with a raw gun---probably if you run 100rnds through your rifle, regardless of how you run them or what you do between, it's likely going to wind up the same, but like I said, there's no sense in NOT doing everything you can to increase accuracy.