Barrel Burners?

[USSR]

Heavy bullets are only needed for long range, 1K. The faster the bullet (more powder) the flatter it flies. Wouldn't pushing heavy bullets slowly defeat the purpose? Wouldn't using lighter bullets and over spinning them be counter productive?

If I wanted to talk to Jim Owens I would go over to his house in Enterprise or see him at one of my matches a Ft. Benning. Oh yeah, I've met Boots as well. Both are outstanding individuals.

Howard,

Yes, to both your questions. But my point is, in answering Wildfires question of

I am wondering if faster twist barrels tend to burn faster ?

it is not the fast twist perse that causes them burn out quicker, but rather the loads used in them. If we took a 1-10" twist .308 and a 1-12" twist .308 and ran similar loads using 155gr Scenar's thru them, I don't think there would be a appreciable difference in wear. Oh, and BTW, I have spoken with Boots on several occasions, and he made my last barrel for me.

Don

 

[Howard Roark]

If every load for every bullet weight for every caliber was at it's minimum would not the stress imparted on a bullet be greater the faster the twist? Wouldn't that cause more friction/heat to check a throat? I think so. The 1 in 6 will erode faster than a 1 in 14.

Will this affect the casual shooter, using normal factory rifles. No.

I know of only one successful shooter to shoot 155's in a 1 in 10. Bergers, pointed. All others use a 13.

 

[Zak Smith]

My 1:12 AWP barrel shoots the 155 Lapuas just fine.

 

[RugerOldArmy]

If every load for every bullet weight for every caliber was at it's minimum would not the stress imparted on a bullet be greater the faster the twist? Wouldn't that cause more friction/heat to check a throat? I think so.

With the lighter bullets, you might be burning more powder to obtain speed in order to make up for the theoretical lower BC of a shorter bullet. The 155 Lapuas might be an exception with what appears to be a longer empty hollow point nose to improve the BC and keep the center of gravity farther back in the bullet, no? At first blush I would expect the light bullets cause erosion more due to larger powder charges in an effort to gain velocity, like pushing 40 Gr bullets in a .22-250 to minimize (in a vain, hopeless, attempt) the lower BC.

I'm a doubting thomas on the friction of a bullet causing wear. I'll buy that slower twist rates are faster barrels than higher twist rates in a hearbeat. The amount of powder burned looms largest in my thinking.

I run a 1-12" .308, but would have never guessed 1:10" would be considered too fast to be competitive. In general, I've always preferred to err on the side of fast twist rates with no regrets so far. I may only shoot at a local level, but my 6mm BR in 1:8" runs right with the 1:14"s and the 1:12"s with the light bullets in SRBR. (Although it likes 70 SMK and 80 Bergers best. I had thought it would like the 107 SMKs when planning.)

 

[Dr. Tad Hussein Winslow]

Bah - I get 75K rounds from my .44 russians!

 

[Wildfire]

Thanks.

Hey there:
I understand the bullet weight and the changes with the twist rates.
But You all have confirmed what I susspected all along . Regardless of a bullet and powder change in a faster twist, The faster twist barrels do tend to allow or create more wear faster. My .223 PSS has a 1 in 14" and a freind of mine has a newer PSS that has a 1 in 9" twist. Mine has had a lot more rounds put thru it and is much older then his. Yet his seems to show some barrel burn. He does run his hotter then I do. And he does use a heavier bullet.
That is why I asked the question. His accuarcy falls of at 300. Mine seems to hang in there much father. I see your points. Thank you.
I must admit I never run max loads. I tune for accuracy only. Power is not an issue with these rifles. Thanks again You all had very good info. I will pay more attention to some of these "F" class shooters. Watching.

 

[USSR]

The 155 Lapuas might be an exception with what appears to be a longer empty hollow point nose to improve the BC and keep the center of gravity farther back in the bullet, no?

ROA,

Yes, I believe the 155 Lapuas are different in that while they are a fairly light bullet, what with the empty space in the nose, they are a long bullet (about the length of a 175SMK). And, it is bullet length, not weight, that determines what a suitable twist is. So, a faster twist than what their weight would normally indicate seems suitable.

Don

 

[Art Eatman]

Wildfire, it doesn't seem to take very much "hotter" to make a difference in throat burn. For example, back when single-base propellants were common and the Swift first got its bad rep as a burner, many people found that cutting back some five percent or a little more on muzzle velocity seriously extended barrel life.

The Swift started with a 40-grain bullet advertised at 4,140. Handloaders who settled for 3,800 or thereabouts noted much better barrel life.

I dunno. Of the 4,000+ rounds through my '06, well over half were light, plinking loads. It's still shooting sub-MOA. Light loads don't really do much in the way of burning the throat, apparently.

Anyhow, color me dubious that the twist rate is much of a factor, if any.

Art

 

[Vern Humphrey]

Three things seem to work to burn out barrels:

1. High pressures and temperatures. Even notorious barrel-burning cartriges will last longer if you back off the throttle a bit.

2. Poor cleaning practices -- apparently excessively fouled barrels generate higher pressures. Clean barrels last longer.

3. Shooting hot barrels -- let them cool frequently during range sessions, and they'll last longer

Very often a shot-out barrel can be cured by simply seating the bullet a bit farther out, because the erosion is in the throat, which effectively moves the throat forward.

 

[Wildfire]

Cool.

Hey:
This confirms my ideas. Thanks for the input.
Maybe some of this will help Auburn also. As he progresses.
I agree on the older powders which are not used much any more. And I always back off on the Velocity.
I don't care if a Varmint wiggles around a little. Just so I can hit him. The .220 swift along with less know rounds like the .22 CHeetah (Jim Carmichels's) round and others were terible barrel burners, back then. But they were in a velocity race. I am not. All of the info you guys have shared will go a long ways with this subject.