Shot out barrel - how do I know?

[AKMarty]

To start this is a question for those who have shot out a barrel. I was watching the online training video on DOPE book use and Frank mentioned that you know a barrel is going when there is a “big” drop off in muzzle velocity. What constitutes a “big” drop off? What other indicators did you see? How did you verify the condition? Were you shooting hot loads, chasing the lands with a short jump, round count, etc?

My rifle is not there yet. Just over 1200 rounds through my Tikka Tac A1 / 6.5CM. -Thanks

 

[b6graham]

groups double for no reason, cleaning doesnt help
velocity drops 50+fps with same load at same temp, cleaning doesn't help

can happen slowly over 200 rounds (course of a match) or over 25

you probably have 400 until you need to pay attention a little more and 800-1200 until it goes. maybe more

 

[verdugo60]

I have only shot out a few but round count dependent on caliber helps you know when to start paying attention. There’s no perfect science and every person has a bit different criteria as far as how much accuracy or velocity loss is “too muc

Things to watch for:
-drop in velocity by 25-100 fps
-unexplained fliers
-group averages opening up
-verified dope suddenly not lining up (velocity)

All this is a good reason to keep accurate records in a data book so you have a benchmark to go off of as well as an accurate round count.

 

[EN2722]

I've personally not shot a barrel out however, the unit I was with had a few go out in my tenure there. Here were some of the warnings and indicators that existed before it was turned into scrap metal.

- It started with groups going from .5" to .75" to over 1".
- Velocity started to decrease. At first, it was ~ 40 FPS, no big deal. Over a few hundred more rounds it dropped over 100 FPS.
- Issues with dope out of guns that guys had shot for 3 or more years.

All guns mentioned above did not shoot hand loads, all M118 LR (DODIC AA11) and it honestly was a fight for the military bureaucracy to deem them "shot out". They had round counts anywhere from 8,700 to 9,400 with regular firearm maintenance on a precision tool conducted.

As @verdugo60 said it's a good reason to be OCD about round counts within your data book for each gun. Something that was honestly neglected in my scenario which was part of why it felt like it happened overnight. Lesson learned for sure.

 

[Ledzep]

Wicked fliers for no good reason and/or worse groups in general. Cleaning doesn't help.

 

[groves]

On my Benchmark barrel in 6.5 CM the first sign was right at 2500 rounds, and it was a velocity drop of 40+ fps, following shortly thereafter with accuracy loss. Chasing the lands didn't really help either.

At 1200 rounds on your Tikka I would make notes on current velocity for your load of preference and refer back to those when you get over 2000 rounds to see if there's an issue.

 

[Steel head]

I’ve torched a few button barrels now.
Usually I’ve had added 1/2 grains or more to maintain speeds then it l get wonky fliers.
Eventually I have to clean it every 50-100 rounds to maintain accuracy and speed is usually down again at that point.
I’m getting up there in round count on my first cut barrel and I think I’m just starting to lose speed.

 

[Dthomas3523]

Depends on your use. There’s dead for certain purposes and then there’s totally dead.

For match use, as soon as I see the first velocity drop, it’s done. Or I I’m close to where I usually see the drop, I’ll use a different barrel for that match.

But it’s still fine as practice or hunting.


And then there’s dead dead, where it’s no good for anything.

 

[RTH1800]

I have shot out many barrels. Some fade, some flame out.
Fading consist of vertical stringing at longer ranges. 500m and beyond. This due to velocity becoming INCONSISTENT.
Flame outs are when bullets go from accurate to key-holing at shorter ranges simply missing the target at longer ranges or seen simply bounding in the dust. This can happen mid string.

 

[Steel head]

It's shot out when you're done fucking with it. After you go through a dozen or so barrels that'll happen faster

^^^^^^
pretty accurate!


LOL!

 

[MakeSawdust]

The first sign of the barrel wearing out is a velocity drop. At that point it is done for some guys. I am cheap, so I will chase the lands and add powder. I call them done when they start throwing fliers and will no longer hold vertical at distance. When they are done done they go from .5-.75 moa at 100 yds to 2+ moa at 100 very quickly.

If I were shooting 2 day matches I would not shoot a high round count barrel in a match. There is too much time, money, effort invested to have one give up in a 2 day match. Local matches aren't a big deal.

Keep a log with accurate round counts for your barrels and don't use them for anything important. I run a 243ai with H1000 with most barrels giving up around 2500 rds. I stop using them for things that are important past 2000 or 2200 rds. As long as you use the same barrel maker, reamer, and load they seem to give up in roughly the same number of rounds and you can get a feel for it after a few barrels. How they are cleaned also seems to play a role, but I have been pretty consistent with that as well.