Regarding barrel wear...

[Slater]

The following is quoted from the current edition of Remington's "Liveready" magazine (essentially a Remington promo/publicity magazine), from an article on the M40A6 sniper rifle:

"There are many variables to barrel life in a bolt-action .308 Winchester, but a conservative number of rounds any one barrel can support is probably right around 7,000 to 9,000. An average 6.5mm short action cartridge might get 3,000 rounds, and a 6mm might get as many as 2,000 rounds."

Is this accurate? Are the smaller calibers really that hard on bores?

 

[lysanderxiii]

The military considers 6000 rounds the minimum acceptable barrel life for the M4.

The end of the life being defined as the group exceeding 7 inches at 100 yards, and the rate of fire being a mix of full and semi-automatic fire.

When you consider a barrel shot-out really depends on how you define "shot out". If "shot-out" means key-holing, then you might get 10,000 to 18,000 rounds before the barrel is worn out, if you consider a two inch group size increase unacceptable, you may get considerably less than 6000 rounds . . .

 

[Bart B.]

Years ago, I got a bunch of barrel life numbers from top ranked competitive shooters as well as Sierra Bullets' test lab data for barrel lives. Then worked up a formula based on three levels of accuracy standards; something that has to be part of the equations. Here's the results.

308 Winchester and its 7.62 NATO sibling:
* military service rifle, 9000 rounds.
* hunting rifle; big and small game, 6000 rounds.
* match rifle accuracy, 3000 rounds.

260 Remington
* hunting rifle; big and small game, 4000 rounds.
* match rifle accuracy, 2000 rounds.

.243 Winchester:
* hunting rifle; big and small game, 3000 rounds.
* match rifle accuracy, 1500 rounds.

.264 Win Mag:
* hunting rifle; big and small game, 1400 rounds.
* match rifle accuracy, 700 rounds

All based on the barrel bore capacity which is the bore cross sectional area in square millimeters being the same number as grains of powder used for normal max loads. 308 Win bore capacity is about 46 grains and that gives 3000 rounds of match grade accuracy. Double that charge weight for a big 30 caliber magnum and barrel life is one-fourth as much; 750. Standard is when accuracy degrades by increasing 50%; if the match rifle shoots 1/4 MOA at 200 yards, its barrel is worn out for matches (Sierra's end of life for its 308 Win test barrels) when its at 3/8ths MOA. Popular benchrest cartridges have powder charges at or very close to their barrel's bore capacity.

Others may have another standard, but lots of folks like this one.

Rimfire 22 match rifles get about 30,000 rounds of barrel life nowadays.