barrel break in

[mattman23]

Just got my ar together, NM 20" and planned to break it in like I was taught.Now I'm seeing alot of people saying its bs.What do you guys think?

[mattman23]

I'm going to break it in,don't want to take any chances.

[NavyBlue99TA]

I totally believe that its a good idea in order to get longer life and a hair more accuracy out of a barrel.  I've never seen a metal part that came fresh from production without having at least a couple rough edges that need cleaning up and that's pretty much what you're doing with the break in process.  As the bullets bite into the brand new rifling, any burs and sharp edges created by non-polygonal rifling processes will break free and cause extra and uneven erosion in the barrel if you don't get that crap out of there.  Is it a huge deal?  Probably not, but it can't hurt especially if the rifle is being used for very long range stuff.

-Rob

[Eric R Shelton]

Clean it, and do a good job.  Don't buy in to the "break in" urban myth.  Here's a quote from Gail McMillan at the Sniper Country forums, who actually makes barrels...

Gale McMillan
Senior Member    posted September 25, 1999 10:10 AM
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The break in fad was started by a fellow I helped get started in the barrel business . He started putting a set of break in instructions in ever barrel he shipped. One came into the shop to be installed and I read it and the next time I saw him I asked him What was with this break in crap?. His answer was Mac, My share of the market is about 700 barrels a year. I cater to the target crowd and they shoot a barrel about 3000 rounds before they change it. If each one uses up 100 rounds of each barrel breaking it in you can figure out how many more barrels I will get to make each year. If you will stop and think that the barrel doesn't know whether you are cleaning it every shot or every 5 shots and if you are removing all foreign material that has been deposited in it since the last time you cleaned it what more can you do? When I ship a barrel I send a recommendation with it that you clean it ever chance you get with a brass brush pushed through it at least 12 times with a good solvent and followed by two and only 2 soft patches. This means if you are a bench rest shooter you clean ever 7 or 8 rounds . If you are a high power shooter you clean it when you come off the line after 20 rounds. If you follow the fad of cleaning every shot for X amount and every 2 shots for X amount and so on the only thing you are accomplishing is shortening the life of the barrel by the amount of rounds you shot during this process. I always say Monkey see Monkey do, now I will wait on the flames but before you write them, Please include what you think is happening inside your barrel during break in that is worth the expense and time you are spending during break in

And here's a link to the Break In/Cleaning page at Noveske.  We're talking about one of the premier AR builders out there- top of the line stuff.  Now look closely and take note: there are cleaning instructions, and not a single sentence about "breaking it in" outside the headline.

http://www.noveskerifleworks.com/care/

Breaking in a barrel is a load of crap. 

[ZEBRA NINER]

Clean it, and do a good job.  

Didn't you forget something Eric? Shouldn't he drag that gun behind his vehicle for a couple of miles? That's a textbook Shelton Break-in technique. 

[Eric R Shelton]

Only if it's through National Match dirt.   

[Christopher Burg]

I was going to post that exact quite that Eric did.  I never bought into the whole idea of breaking in a barrel myself.  The reason why is simply, if I asked 10 people what breaking in a barrel actually did (exact physics behind it not just "it improves accuracy") I got 10 different answers.  Most things that work well have a solid reason behind them that is well understood.  When people claim something is great but nobody agrees exactly why it's great I generally put it down as myth.

Also ZEBRA NINER made a good point, you should drag that rifle behind your truck for a few miles.  If you don't you'll never know if the trigger is safe.   

[NavyBlue99TA]

Holy cow, 100 round break in!  I was talking about something more on the line of 10 rounds tops.  That must have been why I bought into it because if I'd heard 100 rounds I would have known it was BS.  Thanks for correcting me! 

-Rob

[mattman23]

The way I was shown was with 40-50 rounds and ALOT of patches/time.My only experience was with my inherited nm m1a.It was rebarreled with a Kreiger and my father-in-law broke it in to the letter.I just shot a couple highpower matches and got hooked,so this will be my dedicated rifle for that.Just trying to get an edge  .Thanks for all the replies.

[N.U.G.U.N.]

Chris might have some input on this...

[James O.]

Got to agree, break-in on an AR barrel is over rated. Long range or hunting rifle I would then.

[lars1367]

It wouldn't hurt to error on the side of caution would it?  Let's say you don't run a patch through it, or at least a bore snake, after ever couple of rounds...whats the worst that could happen?  If you do damage your barrel or cause it to ware out faster, could you easily replace it at a reasonable price?  Given the current times and circumstances, that's a chance that I'm not willing to take with my weapons just to save a couple of minutes at the range.  Just my $.02
-Lars

[Matt G]

I am no expert but in my opinion, there may be differences if the barrel is chromed lined vs not.  I know black powder rifles perform better, IE more accurate, if they are "Seasoned" a bit.  Like a cast Iron skillet.  Common sense seems to indicate that leaving crap in the barrel for an extended period of time will only screw up the rifling eventually since the grit that is in the barrel turns into "sandpaper" when a round is fired over it.

Matt G

[Chris]

Breaking in a barrel is a tedious PITA. And, a shooter may never truly know whether the time spent was worth it. I do it on barrels that I require produce maximum accuracy and maximum accurate barrel life because of the following.
There are two types of barrels available today – factory and match. The factory barrels are mass produced, installed, test fired and shipped (with copper and powder fouling still in the bore... they don’t clean ‘em). If you run a bore scope through a factory barrel you’ll see machine marks in the bore (most running across the lands) and you’ll see machine marks in the throat (also running across the lands) where the barrel was chambered. Match barrels normally have some lapping done to the bore to remove machine marks, but seldom in the throat.
If these machine marks, bore and throat, are not properly smoothed out they act like a rasp every time a bullet goes through the gun, and you pound copper fouling into those blemishes. The purpose of breaking in a barrel is to allow fired bullets to lap the bore and throat smooth, without accumulating fouling in those blemishes. If that smoothing is not done the gun may shoot well at first, but the accumulation of fouling in the machine marks will build and make proper barrel cleaning difficult. That will, in time, reduce accuracy, and shorten the accurate life of the barrel.
If you take a new barrel, fire ten rounds, and then run an ammonia-based copper solvent through it you’ll be amazed at the sea of blue you see on the patches. That blue is copper. And, as long as those machine marks are there, your patches will be blue forever. If you break the barrel in properly, subsequent cleanings will show very little copper fouling.... and with minimal copper fouling you’ll get better accuracy and a longer accuracy life from that barrel.
Like I said... a shooter may never truly know if the time was worth it. It’s insurance. But, most of the time it’s worth it.
Chris Christian