I seem to get a nice inner core pattern on my SK1 with nearly everything I feed it, from #3 to BB. I don't rely on 2 dimensional patterning, as i don't think it is a true reflection of the shotshell pattern, which is actually a four dimensional space-time pattern, which you have to place around the bird/target . In terms of shells, who knows what I am feeding it. Honestly, most of the kills are within 30 yds, so it really doesn't matter that much. I shoot a lot of Xpert 2.75 and 3" in BB for big geese, but my favorite is the Challenger 2.75 or 3" 1 1/8 #1(CDN brand) load for snow geese. I find you get a decent pattern density with the #1 and good penetration at longer ranges . I also use the SCORE (local MB company) shotshells last couple of years without any complaints. Overall, nothing special, just a wide open choke and some cheap as dirt shotshells.