By all means try to start your test session with clean barrel. The plastic from sabots builds up quickly and will affect accuracy. Secondly, try some different brands of slugs. And last but not least, get a comb raiser so that you can get consistently solid cheek weld and sight picture.
ww.accu-riser.com/categories/Accu%252dRiser-Cheek-Pads-and-Comb-Raisers
