Re: How quick can a .300 RUM burn a barrel out?
I think the RUM's barrel life should equal what folks got with the .300 Win. Mag. in prone long range competition. 1100 to 1200 rounds before the best of them noticed accuracy degrading by about 25 percent. This is based on a new barrel getting sub 3/4 MOA at worst for 1000 yards.
While longer necks of times are claimed to get much better barrel life, in comparing what folks got with the original .30-.338 (.338 Win. Mag. necked down to 30 caliber) to the .30-.338 Keele Mag. (.300 Win. Mag. case resized in a .30-.338 die ending up with a much longer neck on the same body size and shape), barrel life was only about another 100 rounds or thereabouts.