There really are MANY factors that come into play (barrel metal, quality, treatment process, type of ammo, ammo loads, how you clean your barrel, etc etc), but for ball park figures, here is a list of VERY ballpark figures!!
well i know both of my AR-15s have chrome lined barrels
this makes them easier to clean and since chrome is harder it also gives the barrels longer life than regular steel
i think its 4150 chrome moly steel on my varminter?
supposeldy chrome lined barrels suffer in accuracy but i dont think my Bushmaster Varminter would be shootin 1/4 moa if something was killing its accuracy potential
bushmaster claims 20,000 round life (.223s) if proplerly maintained... i havnt put that .223s down either barrel
i might have put close to that much .22 LR ammo down my Bushmaster M4 barrel by now but it should go forever shooting .22 LR and i have only put a few thousand .223 down the barrel
stainless steel barrels are more common and i hear they tend to be more accurate than steel barrels, easier to clean and also last longer than steel barrels supposedly more so if they are cryo treated?
im no expert on barrels and cant really say what advantages/disadvantages of one type of barrel over another
well i i know stainless is easier to clean than a moly barrel and also the barrel life is longer. Accuracy is also better i would asume but i have never seen a rilfe with a match moly barrel. And as for barrel life if u running hot loads it wont last as long. You will burn the throat out also it depends on how hot u shoot your barrel. Lata
Quoting Glenn Newick author of The Ultimate in Rifle Accuracy:
Super accuracy for good benchrest barrels is only in the 1500 round range. Good barrels show competitive accuracy up to 2000-2500 rounds. After that we're fooling ourselves by thinking the rifle is still in top shape, it might win a 20 shooter local match, but it won't cut the mustard at the Super Shoot. Install another barrel and use the old one for practice on windy days where there's two inches of wind drift.