When do YOU deem a barrel to be shot out?

[Hydra6]

I shoot PRS more than I hunt. My experience is that when barrels go "bad" (definition differs), we see a velocity drop (Clue 1), 100 yard groups still ok, but unexplained flyers at 600 yard or so (confirmation). Seen it multiple times at matches including me. Chronoed before match and noticed velocity loss then misses at 600 plus - unexplained like hit, hit, miss by 2 ft. Most common theory is throat gone and fire cracking damaging jackets of projectiles. Depending on cartridge, we pull the barrel before "bad" and save for practice or give to a friend we do not really like . I just pulled a 6Dasher at 2400, a 6XC died in a match at less than 2000. 6XC run harder than Dasher. 65CM barrel that died went much more round count - 3500+.

 

[Cactus kid]

I shoot PRS more than I hunt. My experience is that when barrels go "bad" (definition differs), we see a velocity drop (Clue 1), 100 yard groups still ok, but unexplained flyers at 600 yard or so (confirmation). Seen it multiple times at matches including me. Chronoed before match and noticed velocity loss then misses at 600 plus - unexplained like hit, hit, miss by 2 ft. Most common theory is throat gone and fire cracking damaging jackets of projectiles. Depending on cartridge, we pull the barrel before "bad" and save for practice or give to a friend we do not really like . I just pulled a 6Dasher at 2400, a 6XC died in a match at less than 2000. 6XC run harder than Dasher. 65CM barrel that died went much more round count - 3500+.

How fast (how many rounds) do you notice a barrel goes from fine to not fine- going from humming along to decreased velocities and accuracy?

 

[Hydra6]

How fast (how many rounds) do you notice a barrel goes from fine to not fine- going from humming along to decreased velocities and accuracy?

In my world of shooting matches at 100 rounds per day, it is like a light switch - ok then bad. If I was hunting and not shooting high round counts, suspect the "bad" would take a while sneak up on you.

I suggest key is chrono graphing speed regularly and watching for velocity drop. I chrono every range event. Some of my buddies chrono at start of match and at end of match. This assumes you keep a standard load and know the velocity.

I cannot see many hunters burning up barrels unless they shoot a lot of practice and/or "barrel burning" cartridges. I shot my 65CM for a long time waiting for it to go bad.

223, 308, similar last very long time. 65CM/260 last a while. My 26 Nosler - assume less than 1000 (maybe much less) but I shoot it a few times to confirm zero and then hunt.

 

[Cactus kid]

@Hydra6 This is consistent with what i have observed. I havent burned out nearly the barrels you PRS guys do, but I shoot my hunting rifles a bit. Ive noticed the "light switch" from good to bad happen in like 50-100 rounds consistently.

 

[mxgsfmdpx]

If you're shooting often enough with known/good guns you will know very quickly in most cases when a barrel is EOL. This can be easy to confirm on a 100 yard range with large sample size groups. A good chrono with good and reliable ammo can very telling as well.

It's tough to put a "spec" on it via "MOA" but generally once a gun starts repeatedly deviating from it's 100 yard "cone" with clear outliers (with outlier shots likely matching a decent sized chrono deviation at the same time) it's time for a swap.

 

[TaperPin]

Is barrel "burn out" a slow, steady process? Does a barrel continually get worse or does it just get less accurate, lose some velocity and just kinda exist in that state for awhile?

Yes and no. When the steel in the bore gets really cracked and jagged I’ve seen photos where chunks have broken loose and accuracy took a noticeable dip over night. Some barrels will erode very evenly and many inches of the barrel will be rather smooth, yet accuracy isnt bad. Other barrels erode heavily in certain spots and it’s not even at all.

Usually my accuracy is relatively consistent and slowly gets worse most of the barrel’s life, then reaches a point it goes down hill quickly. When a 7 mag gets noticeably larger groups within 100 rounds, every 100 rounds after that will be worse than the last.

Going by velocity loss can be hard for a hunting gun if lots of powder, or entire loads are changed many times in the barrel’s life. I don’t know many guys that chrono loads every 100 rounds.

It’s not talked about much, but some of the accuracy loss is due to slow erosion at the muzzle, from gasses trying to rush around the bullet as it is just leaving the barrel. Some high volume shooters have the barrel shortened slightly and recrowned to extend the life a bit - some claim it adds 20% to the accurate usable round count.

It’s also not talked about much, but in some circles at about what would be normally the halfway point in it’s life, a barrel is essentially cut and rechambered to remove the worst of the erosion right at the throat before it becomes an issue, then it’s done again at the normal full life of the barrel. That’s a lot of work, but 50% longer life is often claimed. I’ve always had the impression this mainly makes sense if the person owns their own lathe and has more time than money. Light varmint and heavy varmint profiles have a longer straight section right after the receiver, partially to make it easier to chop and rechamber.

 

[wyosam]

Depends entirely on what it’s used for. If it’s a gun that needs to shoot tiny groups (competition, long range, etc), it might get pulled as soon as it falls off from its peak performance. A hunting rifle that gets used in tight country mostly that starts out shooting very small groups can degrade a bunch before it starts to matter.


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