I use a Truglo .565 in my son's 1187 Compact. With a 1 5/16 oz load of 9s he got ~250/130 in the 10/20. Still trying to figure out where the other 90 or so pellets are going.

"Any way you look at it, most of the problems facing baboons can be expressed in two words: other baboons" -
D.L. Cheney and R.M. Seyfarth