Air Venturi avenger slugs .22 or .25

You will have to experiment with slugs a bit to find one that works well with the stock barrel. I shoot 29 grain NSA slugs in mine mostly. I have tapered the lead in to the rifling to make chambering slugs super easy. They get pretty deformed by the fairly hard shoulder in the stock Avenger barrel. This takes away from the B.C. and accuracy. Mine will now shoot any NSA slug very accurately and I can turn it up to over 70 FPE after some porting of the barrel and valve block. It's almost as accurately as my MKII Impact .25. The trigger is now the issue. The shorter slugs chamber up better from my experience with a stock Avenger.