I found, that when I shot 2F in my pistols, they got a lot hotter then with the same amount of 3F. I think it has to do with the bigger grains leaving more room for air and that causes a hotter burn. But, I really can't say for sure. I just know it happens!
The way I keep from frying my off hand on the barrels is to lace a THIN leather sleeve around the barrels at the level of the forestock.