Yeah it would be a pretty short life barrel but as you say, it's not like you would be benching it a whole lot. A good quality barrel in 6.5-300wby would probably get you 3000-5000 rounds (rough guestimate) as long as you weren't seriously hot rodding the loads. Maybe more. I had around 3200 through my old 6.5-300 win mag before I sold it and it still looked very good in the throat and rifling. BUT I was always VERY diligent in my loads and I fire formed all cases for it. I also set the jump VERY close since it liked that the best anyway.