I have been doing alot of research on the topic of "barrel life".... here is the conclusion of my research,
the faster the bullets = the faster the barrel dies
I know this doesn't tell you much, but here is some more info; I spoke to alot of people about this, most of them were competition shooters SO they know what they are talking about.....Most of them said that alot of the newer barrels produced today, will take a pounding of anywhere from 6000-10,000 rounds (in a standard caliber, like a 30-06). I say 6000 to 10,000 becuase it depends on how you shoot, if you let the barrel cool between shots ? how hot your loads are ? and this is the most important key, DO YOU CLEAN YOUR BARREL AND TAKE CARE OF IT......
Other competition shooters (those who are fanatics and must place thier bullets WITHIN millimetters, and if they are even 2 millimetters off, they consider thier barrel's "bad")... those guys said a typical standard caliber (a 30-06 for example) will last you up to 2000-3000 rounds of "amazing accurasy".
Of course, since most people are hunters, and they don't care if thier bullets are a few millimetters off here and there, they can hang on thier rifles for up to 6000-10,000 rounds.
However, the numbers are totally flipped upside down, AS SOON as someone brings up the same topic but a faster "magnum" like the weatherby / ultra mags / or even the standrad mags like the 300 win mag.
Alot of folks "think" that a fast magnum bullet will kill your barrel anywhere from 1000-2000 rounds ( I dunno if i wanna agree with that, but I haven't shoot my 300 RUM that much, I think I put about 150 rounds through her lol)