That's a tough question to answer. Much depends on how the barrel is treated. Conditions that effect barrel life are, how hot the loads are you shoot through it, frequency of cleaning, whether or not you use a bore guide for cleaning, how hot you get the barrel shooting (shooting lots of rounds close to each other). I can see a 22-250 barrel shooting very accurately for 1500 rounds, maybe more. Same thing for the 223 barrel.
Don