I found a really accurate low speed load for my 300 win mag for our wisconsin whitetail season. Most shots are under 75 yds and I don't like blowing up deer. The load is 80 grains AA8700 under a 180 hornady and it clocks 2500 fps and is super accurate. With my burris ballistic plex the crosshairs match up nicely for 100,200,and 300 yds shooting. It was so accurate I broke 2 out of 3 clay birds at 300 yds (nice to know just in case I post on a field). Anyhow when cleaning I noticed I got way more black out of the barrel on my patches than normal and way less signs of copper fouling.....almost as if the bullet is riding on powder residue instead of the barrel. Surprisingly the case mouths weren't terribly sooty and they must have expanded fine to seal off the chamber. So.......I know you guys play with some slow powder here...do you think I'm just headed for an eventual build up of bad things in the barrel or should I take my fun load and run????