In my part of the world barrel life is quite an issue due to legislation. Have just fitted a new Border (Scottish) barrel, shot count now about 250. I'm shooting mild loads, Sierra MK 175gr @ 2880 fps (28" barrel), absolutely no target shooting, just hunting, not more than three shots in quick succession, if at all. We use a locally developed Powder, the same as your 4831SC, my load is 61,5 gr. Can anyone give me a fairly accurate estimation of barrel life, from own experience etc.? I'm cleaning with JB & Kroil, occasional Robla Solo, only patches, no brushes, about every 40 shots.