How do you know when your barrel is worn out?

[Kwanger]

I've got a rifle with a recommended barrel life of 6000 rounds. It's had that through it and more, and it shoots just as well as it always has.

So how do I know when its worn out and needs replacing? Is it just that your accuracy nose dives? Also, is it dangerous to shoot a barrel past its stated life?

 

[Dr. Tad Hussein Winslow]

Is it just that your accuracy nose dives?

Yep.

Also, is it dangerous to shoot a barrel past its stated life?

Nope.

Next question!

 

[longdayjake]

recommended barrel life can often be the same idea as lather, rinse, repeat that you see on shampoo bottles. The idea is just to get you to buy more before you really need to. If it is still working and you have no complaints then keep at it.

 

[jhco]

accuracy suffers, and you should be able to visual see a difference

 

[briansmithwins]

Barring external damage like crown wear barrels wear out at the throat. Once that goes group size will open up, often dramatically.

A bore scope can see the wear but until group size increases the barrel is still 'good'. What group size you're willing to live with depends on what you do with the rifle.

these things wear a bore faster: small bore, high velocity, hot burning powder, rapid fire.

BSW

 

[jd46561]

When your bullit hits the target sideways, its time for retirement.

 

[Vern Humphrey]

I've got a rifle with a recommended barrel life of 6000 rounds. It's had that through it and more, and it shoots just as well as it always has.

Then it's not worn out. When accuracy starts to deteriorate, just seat the bullets farther out to compensate for the worn throat, and it should continue to shoot well for another few thousand rounds.

 

[krs]

Benchrest competitors use 5000 rounds as a place where they start expecting that their barrel's wear may be affecting their group sizes, but it in no ways means that the barrel is bad. There have been barrels that have remained competitive at over 10K, and a few guys who say that they've had barrels that still shot well at 15K, or even 25K (In one case I remember reading about).

But.....benchrest shooters expect their barrels to enable them to fire five shot groups at 100 yards that measure .200" or better over and over reliably. Most anyone else would be happy to have a rifle that gave them solid 1/2 MOA performance, or even 1 MOA.

I wouldn't condemn a 5000 round barrel, but if I was sure it wasn't shooting as well as it once did I'd be looking hard at the likelihood of copper fouling. This is where a good borescope, or hiring someone with the borescope and knows what to look for comes in.

Hotter the caliber or load the faster throat erosion will take place.

 

[mp5a3]

Small Arms Review did a torture test where bullets were literally hitting the target sideways. I always thought people were joking about that

 

[rcmodel]

Barrels shoot out beginning with throat erosion right in front of the chamber. It is caused by the intense heat & sand blasting action of the burning powder grains.

You can actually see it as an orange peel or a "frosted" appearance just by looking through a clean barrel from the chamber end.

Accuracy is effected because as throat erosion progresses, the bullets have to make an ever increasing jump from the chamber to the beginning of the good rifling.

When you can start to actually see it, the barrel is on the way to going south.

The rest of the barrel is not shot out, and in fact could be cut off and re-chambered and still shoot quite well.
That's where I used to get my match grade sporter barrels when I was in the service.

My AMU unit had a 55 gallon barrel full of shot-out 30-06 Model 70 match rifle barrels. Cut off the chamber end, taper to a sporter conture, and fit them to a 98 Mauser and you could start all over again with a practically new, and great shooting .308 Win barrel.

rc

 

[Kwanger]

Good info guys - thanks!

 

[Jim Watson]

All you can do is shoot it until it no longer gives satisfactory accuracy.

I saw a barrel wear out.
The shooter tried to stretch a 4600 round barrel to 4700.
It didn't work, it would not hit the 6x6 target backer at 1000 yards. He said it was doing ok the previous week's match.

A friend said he had one wear out over a weekend match although I do not recall the round count. Normal on Saturday, scattering shots on Sunday. He could not have it set back, it was on an M1A auto.

I am told that the AMU replaces service rifle barrels at 2500, long range at 800.
They do not want to take any chance of a barrel fading during a match. It's not their money, anyhow.