sweet, that .660 constriction works great in my gun also, similar numbers with Hevi 7's...make sure you get the sighting right, I whiffed on a bird (got him on 2nd shot but just barely) because my sight set up was a little screwy and uncomfortable for me to aim properly. Wouldn't matter at 30-40 yards but at 20 with a 6 inch wide pattern I shot over him. Good luck keeping the blood off your boots carrying your bird out witht that bird crushing pattern!