From your experience what has the greatest impact on accuracy, a cold barrel vs a hot barrel or a clean barrel vs a fouled barrel. I once owned a H&R single shot .308 that would shoot 6 inches below the bullseye with a clean, cold barrel. The next shot would be about three inches low and all the rest would group 1-2 inches in the bullseye. I don't know if it was fouling or heating that changed things. I currently own a Ruger scout .308 with laminated stock. Today out of a fouled barrel, I shot 10 rounds of 110 grain bullets and 10 rounds of 165 grain bullets. With each bullet I shot 2, 3 shot groups and 1, 4 shot group. In both cases the 4 shot groups, which were the last groups, shot more accurately. This rifle only has iron sights, and I was shooting 100 yards over a sandbag, so it could have been me getting in a groove, or perhaps this gun is more accurate when it heats up. Any ideas?