I saw on a hunting show that stated a barrel will be broken in after about 200 rounds, so from 0-200 groupls should get better, then after somepoint maybe 2000 rounds itll get worse. But I'm not sure, I think jarret rifles say they'll shoot the best from day 1. All I can suggest is spacing shots, letting the barrel cool, or at least not overheat, don't just blast 5 rounds in 30 seconds. I read somewhere that after 3 quick shots of a .257 wby, water will boil off the barrel. heat is what will really increase wear/ ruin a barrel. keep it clean, but I don't think you need to go overboard, just after each day of shooting?