Breaking in a .556 or .308

[pewpewfever]

I’ve heard it takes about 200 rounds to break in something like a creedmoor, and then the barrel is good for another 1800 rounds or so.

For tactical calibers, like .556 or .308, do they also have to be broken in before they get up to speed and exhibit consistent muzzle velocity? If so, how many rounds does it take? I hear a tactical caliber barrel is good for about 8 to 10 thousand rounds, so dies the break in require 4 or 5 times as many rounds (i.e., 800-1000)?

 

[padom]

None of them have to be broken in. Go shoot them.

 

[Rlandry]

Ask 10 people and you will get 10 different answers. Go with the barrel makers recommendation, or if you have a regimen you are happy with use it.

 

[TonyTheTiger]

Whut?
Tactical calibers?

 

[pewpewfever]

Whut?
Tactical calibers?

In competition, there is a tactical category based on caliber, so yes.

 

[brianf]

“Usually” take that for what it’s worth a factory barrel takes 200ish to really shoot to its best

It’s not velocity spread it usually gains some speed after that point when compared to new.

Has nothing to do with the life of the barrel, it’s just shooting out machining marks/scratches.

223 and 308, just go shoot and have fun, don’t worry about it.

 

[pewpewfever]

I'm aware of that but I'm not certain thats what the OP is getting at.

I am the op

 

[TonyTheTiger]

I am the op

You're right, an oversight on my part. Prior post deleted.

 

[pewpewfever]

You're right, an oversight on my part. Prior post deleted.

Class act

 

[Almonz]

My break-in procedure is put ammo in magazine, charge rifle, and shoot. Seriously though I remember Krieger himself actually talking about barrel break-in during an interview and he said more or less it's something people do to just feel better about themselves. There are people that swear by it but I guess I don't shoot at their level of expertise.

 

[pewpewfever]

The PRS competitors I know who shoot creedmoor or other high BC calibers frequently test muzzle velocity (MV) and have observed how it changes over barrel life. According to them, the first two hundred rounds, you see MV increase. Then, for the next 1800 rounds or so, MV continues to rise more slowly, and the standard deviation is smaller. Eventually, at about 2000 rounds, you see the MV start to go back down, and so you know it’s time to get a new barrel. Shorter projectiles, which have lower BC, don’t wear out a barrel nearly as fast as a creedmoor does, and maybe barrel break-in is not much of a concern with those projectiles. That’s basically what I’m asking here.

 

[cornhusker86]

BC has nothing to do with it. Bearing surface of the projectile and the amount of powder being burned are the factors at play.

 

[Rlb40x]

I do a 20-30 shot break in because I have nothing to loose by doing so.
I shoot one then wet patch and bronze brush for 5-6 rounds. Then I go to 3-4 shot groups, cleaning between.
The way I look at it is, if I didn't do it and my rifle shot a solid 1/2 MOA, I would wander if it would have shot 1/4 MOA if I had cleaned the copper out the first few shots.
My last new barrel was a Shilen select match in Valkyrie and it shoots very small.
Most good custom barrels are very smooth to start with and I don't see much copper when breaking in. I've done it on Shilen, benchmark, rock creek, muller and Broughtons.
It may not have helped, but it sure as hell didn't hurt them.

 

[flyer]

In my opinion, break in is when bullets and burning powder polish out the machining marks left over from manufacturing. When done properly it prevents copper fouling and fills any remaining marks with carbon fouling.

The thing is every barrel is different so break in procedures that work for one barrel might be too much or too little for another.

If you have a really rough bore, break in might be a very good idea. If you have a hand lapped and well polished bore, it might be ready to go right away. Most will be in between and then j think it makes sense to look at the bore before and during the break in to see when you're done.

I broke in one Criterion barrel with 13 shots and 2-3 uses of JB bore paste. Now it fouls very slowly and barely picks up any copper. If I had followed a break in procedure, j would have put a few extra rounds of wear through my barrel. If it had been rougher, I would have kept going.

 

[Greg Langelius *]

I don't do break-in anymore, despite being more or less committed to factory rifles/barrels.

What I will do is to dedicate the first 100 rounds to fireforming a batch of brass for load development over the next 100 rounds.

Greg

 

[Steel head]

Get a case of ammo, shoot it.
Break in is done.

 

[DarrinW]

Look up the 2017 shot show interview with John Kreiger with Long Range Shooter of Utah on YouTube. He shots a few and then cleans until the cleaning patches say it’s ready. There is no rote procedure. Or don’t. All you’ll have is a little harder time cleaning it the first time. According to him bullets traveling down the barrel don’t harm it, it’s all the unburned powder sandblasting the barrel.

 

[pewpewfever]

I was just thinking of break in as a certain number of rounds fired, not the fire and clean procedure I’ve seen described here and in some articles.

 

[TheGerman]

 

[bfoosh006]

I can't say I have ever followed any barrel break in guidelines... but the best groups I have ever shot were after a through cleaning.

I realize that is a different subject.. but ...

Also I am believer in seasoning the barrel bore to the ammo being fired ( fire 5-10 rds of the specific load ) ... prior to attempting to shoot for precision testing.

 

[oldfatguy]

Broke in a 260 Rem GAP Crusader. No copper after the second round - done. Still shoots 3/8 MOA.
And then there was a Rem 700 SPS Tacticle 223 that was showing copper after 20 rounds of one-and-clean.

OFG

 

[flyer]

As a member of the acting poor over here society, some cheap stuff isn't hand lapped and polished.

Some of them are bad enough that if the condition isn't addressed it will be a pain in the butt to clean it and may be inaccurate.

It's hard to say how much a break in helps accuracy but it probably won't hurt and it might extend the life of a barrel if it needs less frequent cleaning because cleaning wears a barrel too.

If you're trying to be serious about accuracy it makes sense no matter how much you spend.

 

[pewpewfever]

To some extent, I come from an airgun background. In Olympic pistol, you have to “lead in” a barrel by firing a sufficient amount of lead pellets, and over cleaning is strongly discouraged. I received similar advice recently about cleaning the copper out of a firearm barrel. There’s so much conflicting advice out there. IDK what to think.