Hello, I'm looking for advice. I shoot a 7mm using H1000, 215m,WW brass, and after even 30rds. down the barrel there is very little carbon build up. This is a near max load, too. In my 243Win shooting IMR7828ssc,215m,WW brass I seem to get a lot of carbon fouling, not sooty like I've seen with Retumbo, but still a lot after shooting only 12rds. I use GM Top end to get the carbon out when cleaning and it takes at least a dozen patches to get it clean using a 15min. soak in between patches. There is little to no copper fouling. Should I look at a different powder? What causes lots of carbon build up?