An 8" twist barrel with the 80gr VLDs makes a good, up to 1000 yard combination. Barrel life is in the 700 round range. As long as you are only using it for long range shots, no problem. By the time you get the bench set, range the yardage, check the wind, adjust the scope, etc., 10 shots an hour is about the best you can hope for. 70 hours of actual shooting will take most people a long time to do.
Jack