Powders that accelerate wear in 30 cal Barrels

Shoulder angle and neck lengths probably have more to do with barrel life than powders we burn. Look at the 243 win and 300 Weatherby! The big Weatherby case holds almost twice the powder but the long neck and radius on shoulder give it similar barrel life

Ageed okie man. Case and chamber design play a role. No one can completely prove it, but the suggestion is that the angle of the shoulder and short neck of the 243 puts the flame concentration point near the lands. If this is accurate, then something that may increase the barrel life of some of the Weatherby cartridges it the extensive freebore they have.

okie man said:

Shoulder angle and neck lengths probably have more to do with barrel life than powders we burn. Look at the 243 win and 300 Weatherby! The big Weatherby case holds almost twice the powder but the long neck and radius on shoulder give it similar barrel life

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Hmmm...Never thought about that. Ok THANKS okie man. I guess I'll just keep going and re-barrel when I need to...LOL...If I live that long...lol

Tiny Tim said:

Ageed okie man. Case and chamber design play a role. No one can completely prove it, but the suggestion is that the angle of the shoulder and short neck of the 243 puts the flame concentration point near the lands. If this is accurate, then something that may increase the barrel life of some of the Weatherby cartridges it the extensive freebore they have.

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I agree that claims about flame-jet angle having a material effect in case life seem to be speculative at best, with little evidence.

I was under the impression it was to reduce pressure by giving the bullet a running start before it contacts lands!

Tiny Tim said:

Ageed okie man. Case and chamber design play a role. No one can completely prove it, but the suggestion is that the angle of the shoulder and short neck of the 243 puts the flame concentration point near the lands. If this is accurate, then something that may increase the barrel life of some of the Weatherby cartridges it the extensive freebore they have.

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I'm late to the party, but I always start these things with....what is shot out? Shot out, to me, is when for a single load, the rifle shoots worse than I will accept.

Finding a load that shoots best is extending that life.

If I will accept 1.5" accuracy from my hunting rifle and it shoots 1" with my best factory ammo, it is 2/3s shot out. If I make ammo that shoots 0.75" groups, now it is 1/2 shot out.....Over 100's of shots, it will degrade for the same load. When you get to 1.25", you might play with the load and bring it back to closer to 1"....you just gained useful life. At some point it will not shoot under 1.5"...no matter what you do. That is shot out.

You can change your acceptance level from 1.5 to 0.5 or 3 and those will affect your amount of shot out.

The final thing to remember is that barrels are consumables. You can buy another for about 25% of rifle cost.

You are correct about the reason for the free bore okie man. I was speculating that it may also have a un designed benefit.

My gunsmith runs N570 in all his Magnum builds. He says that he's observed 0.003 throat wear per 100 rounds. He's around 300 on his norma improved, and has lost close to 0.01 of throat. I have a LOT of N570, N565 and RL26 so let's the steel degradation begin!

Is stainless more or less resistant to this type of erosion? Does it matter?

Less according to Krieger!

okie man said:

Less according to Krieger!

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That's news to me. Good news as my 300 win is stainless.