Barrel question

My answer would be not really. Some really hot chamberings like 22-250 are known to be harder on barrels than others, but barrel life has mostly to do with things like steel quality, lining treatment (if present), bullet material, powder burning characteristics and rapidity of fire. All other factors being the same, I seriously doubt a barrel chambered .308 Winchester in will last significantly longer than one in 30-06, .270 Winchester, .35 Whelen or some other reasonably similar cartridge.

That likely also holds true if you are just talking .308 as a bore measurement rather than specifically about the .308 Winchester cartridge. Other bore sizes in the 7-8mm range will probably last equally well provided all other variables are the same. I imagine there is an old military study on this somewhere.

.22 rimfire and pistol-caliber barrels would suffer erosion and wear less quickly than higher pressure rifle cartridges, and a well-treated air rifle barrel would likely last indefinitely, but that's apples and oranges.

Incidentally, the Soviets experimented with a smooth bore barrel for a flechette-firing platform that was evidently very resistant to erosion (go to about 22 minutes into the following video):



Also there is the question of what constitutes barrel life. Are we talking lifespan in terms of best target-level accuracy or just basic functionality? Water-cooled machine gun barrels have had documented functioning for over a hundred thousand rounds of near continuous fire, but their bore's rifling would have eroded beyond recognition after firing a fraction of that number:

https://www.popularmechanics.com/mi...rs-gun-is-one-of-the-best-firearms-ever-made/

I know the US Army M24 barrels often lasted WAY beyond the expected service life- still holding 1 MOA of accuracy. The 300 win mags... not so much.

Expansion ratio and case volume. Both are in the low catagory for a bottle neck round in the 308, so the bbl live in longer than many others rounds with greater case volumes and/or higher expansion ratios.

The more powder you burn the faster a barrel wears out. A smaller diameter barrel in relation to powder burned will wear out faster. A 30-06 or 300 WM burn a lot more powder in the same diameter barrel as 308. Relatively speaking a 308 will last a lot longer than either, and a 30-06 will last longer than a 300 WM.

But all of those still have pretty long barrel life. When you start burning the same amount of powder in smaller calibers then you start burning up barrels fast. A 25-06 for example has roughly the same amount of powder as 30-06, but with a much smaller barrel diameter. Same as 243 vs 308. A 243 or 25-06 barrel will wear out a lot faster than a 308 or 30-06 will.

A 308 is generally one of the longest lasting due to fairly low powder charges in a medium bore size. Most target shooters expect about 5000 rounds before accuracy starts to degrade, but you'd still get more than acceptable hunting accuracy for at least 10,000 rounds. Some of the really fast 6.5 cartridges such as 264 WM will wear out a barrel in 1000 rounds or less.

It used to be the accuracy life of a 308 Win was close to 5000 rounds in NRA Across the course competition. However, about 3/4 of the rounds fired in an XTC match were reduced loads. You fired nice soft loads standing and sitting rapid fire at 200 yards. You did not need or want to crank up the pressures during 300 yard rapid fire, as getting knocked out of position, and having tight case extraction, was bad to your score. The six hundred yard stuff was the hottest and it was only 20 rounds fired slow fire.

However, talking to my F Class buds, they are pushing 308 Win's as hard and fast as they can, they are shooting 200 grain bullets, and barrels are wearing out in around 1000 rounds.

That surprised me, but I shot in a different period when fewer of the loads were maximum.

A 338 Fed should last notably longer than a 308win. A 45-70 far longer than a .308, as will a 30-30. 6.5 Grendel and 6x45 should last longer as well... 7-30 waters and 7 BR too.

There’s nothing unique about barrel life in 308win. It’s a relatively low performance round with relatively low expansion ratio or “overbore ratio,”and relatively small charge weights, so it lasts longer than most high performance rounds. But there are many cartridges with lower expansion ratio, and many with lower pressures and lower powder charge weights.

Do you know why we thread barrels onto receivers? .....so you can put a NEW barrel on!!!!!
If you are shooting enough to wear out the barrel.... WIPPY! Super....and I am trying to wear out three right now! God bless you and put a new one on and give er another go......just screwed on another 26 Nosler on and breakin it in....

Generally speaking, a .308 is easier on barrels that many other calibers. It's one of the reasons that I chose a .308. That's not to say that you won't toast the throat though. With my Krieger stainless barrels on my 700, I could get two rechamberings before I had to replace the barrel due to the bore being shot out. I may have been able to go more, but at that point, I got more than my money's worth out of the barrel.

Barrels are a consumable. Incandescent has washes steel away in the throat until enough is gone that accuracy falls off.

The smaller the bore and higher velocity the shorter the barrel life. The type of powder also has a significant affect. Hardchrome and nitride offer some protection but even those will get damaged eventually.

I expect my .223 Rem barrels to last 10-20k rounds before needing to be replaced. I expect the 7.62x39 to double that. The 9mmP PCC barrels I don’t expect to shoot out in my lifetime.

BSW

briansmithwins said:

The smaller the bore and higher velocity the shorter the barrel life.

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Why does 223rem have nearly twice the barrel life of the 6mm Dasher, which a) uses the same powder(s), b) has a larger bore, and c) has slower velocity?

6.5CM will also burn out a barrel long before a 308 barrel for the same amount of rounds.

Varminterror said:

Why does 223rem have nearly twice the barrel life of the 6mm Dasher, which a) uses the same powder(s), b) has a larger bore, and c) has slower velocity?

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I suspect the difference is in the definition of ‘shot out’. For most shooters they are going to swap AR barrels when they start getting groups over 2MOA or so. It looks like the 6mm Dasher is used by guys that would be wanted better groups than that.

BSW

I believe the .257 Weatherby Mag. may be one that is especially tough on barrels.

taliv said:

because it's more about being overbore. the size of the bore relative to the size of the case. for example, take same caliber, same velocity, but one case long and skinny and the other a super short and fat one, and the long skinny will have better life.

i don't have data to prove it, but i strongly suspect, the powder has a significant role too. some powders burn "hotter" "flame temp" than others. sadly, some of my fav powders are some of the hottest, and i've been trying to get the same results with cooler powders

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I vaguely remember an article talking about single, double, and triple base powders and their effects on barrel life time. There are additives that will reduce barrel wear as well, but those bring their own problems.

BSW

@taliv - I was being facetious. The “smaller bore and higher speed” wives tail gets kicked around far too much without considering what is really going on. Overbore ratio matters far, far more than the oversimplification @briansmithwins has offered above.

briansmithwins said:

I suspect the difference is in the definition of ‘shot out’. For most shooters they are going to swap AR barrels when they start getting groups over 2MOA or so. It looks like the 6mm Dasher is used by guys that would be wanted better groups than that.

BSW

Click to expand...

Nope. Doesn’t play out that way for guys shooting F/TR class.