Velocity and barrel life?

[Tropical Z]

Particularly concerning the new 204 Ruger.This round as i understand it will send a standard bullet weighing 32gr down the barrel at 4225 fps! This should give the 17hmr some competition for a small, fast round.However,dont barrels really take a beating at these velocities? What is the likely lifespan of a 204 Ruger barrel?

 

[mete]

One way to lengthen barrel life is to not fire rapidly. Heat shortens the barrel life . It is not "erosion" (the wearing away of the barrel) but heat damage that shortens barrel life. But 4225 ? that will have a barrel life like the 22 swift ,not too great .

 

[MLC]

Cartidges that are extremely overbore to achieve velocity are more prone to throat erosion than ones that have inherently high velocity due to lightweight bulets.
Look at the 223 and 243 WSSM's they chrome lined the bores on those rifles because of the amount that they are overbore and it's detrimental effects on the test barrels.
It takes a relatively small powder charge to spit out that tiny .20, so long as you aren't stuffing the case to the absolute max the bore should last quite a while. Mete has it right about getting your bore too hot, but, with the small powder charge the barrel on a 204 will not get as hot as 22-250,220 swift or 243 barrels. Lots ov Varmint hunters either have a 223 as a second rifle or use it exclusively because it doesn't heat up as much.

 

[Art Eatman]

"I've always heard": Super-zoomer cartridges seem to run 1,200 to 1,500 rounds of quality accuracy in barrel life. Could run on out toward 2,000. At some point the throat has burned a bit. The common fix is to set the barrel back a turn or two, and re-ream the chamber.

Art

 

[cheygriz]

I agree with the majority here. Heat is the enemy. if you let the barrel cool between shots, it will last longer.

I've seen a couple of "Rambo types" burn out the barrels in M1As by loading up a bunch of 20 rounders, and emptying them "from the hip" as fast as they coud pull the trigger.

One joker ruined the barrel on a match grade M1A in less than 1200 rounds. Most folks I know get at least 2,000 rounds and usually over 3,000 out of an M1A match barrel B4 accuracy drops off.

A 4,000 + fps barrel isn't goint to last as long as a 7.62X51 barrel, but keeping it clean and keeping it cool will extend it's life significantly.

 

[Archie]

Okay, I'm being pedantic...

It is indeed heat that washes out the leade from a rifle.

More pressure equals more heat. So it's not velocity so much as the pressure to get that velocity. Higher pressure rounds generate more heat than lower pressure rounds.

Let the barrel cool between shots, and certainly between strings.

 

[P95Carry]

Temperature as has been said .. worst enemy ... and with high pressure rounds pushing the velocity envelope .... I like to think of it as a form of gas erosion.

For sure .. the throat is seemingly where all the life shortening takes place for most part.

I have heard it said that the hyper velocity .17 rem .. promotes rapid barrel degredation .. 2,000 rounds max some say ... but i have no personal experience of that.

 

[mete]

P95, It is not erosion. There once was an excellent article in the American Rifleman which was a detailed metallurgical study of "eroded " barrels. What happens is that the barrel steel actually absorbs carbon from the hot combustion gases. This then changes the steel and causes cracking etc.

 

[P95Carry]

Aha ... so metallurgical changes. I wonder what is the situation with good quality chromed barrels, where the steel has that layer of protection.

 

[Tag]

in researching my upcoming Mauser purchase I've heard tell that throat erosion, while certainly a detriment to accuracy, is not necessarily the as bad as muzzel erosion. This makes a kind of sence, as the gasses propeling the bullet would not be exiting the barrel uniformly.

I was worried about barrel life too, 300 WSM, but then again, by the time I've put enough down the tube to kill the barrel I will have paid for the gun several times over in ammo costs.

Keeping the temperature down seems to be the only medicine.

It seems like alot of old (30, 40, 50 years +) 30-06's are still alive and kicking. I suppose there is a big difference between benchrest/competition accuracy and what the majority of rifle shooters expect.

As long as my Winchester will put three into a 1.5 inch area at range I'll be more than happy to keep shooting it.