I just came back from Montana from a great shoot. This is my 6th year of prairie dog shooting and I never stop learning from my experimenting with loads. In shoot a 243 AI and a 22-250 AI built on Stolle actions with Kreiger barrels. I personally like the 22-250 AI best with 50 Gr Noslers and 40 gr V-Maxes when I fire form. What I found out with the 50 gr Noslers and IMR 3031 powder is that you do not have to clean the barrel much. When the bullets start spraying, it is because the barrel gets too hot, not from being dirty. After it cools the gun shoots dead on again. The cleaning does not make much difference. The same thing for my 243AI with 55 gr Noslers. This new information for me made my shoot much more fun since I knew what was really going on. Both guns have about 4000+ rounds fired. My buddy shoots a Remington 22-250 also with 50 gr Noslers and 3031 powder---same results. We shoot about 1000 dogs in 3 days together. Comments? Questions?