Also tried carlson .575, undertaker .575, primos maximum .570, super full remington .572 and non were worth a hoot. From what I have read here on OG it looks like something in the range of .550 to .568 does best. Carlson's new choke for 20 gauge longbeards is .568. SSX is .550 or .555 range. Also something ported looks like it might be best. I will wait and buy another choke in May from trulock or carlson and take from what they recomend. Buford