I have a SX2 and shoot a .680 Trulock Precision Hunter with the LB XR 3 1/2" #4s, and a .670 Trulock Precision Hunter with the LB XR 3 1/2" #5s. Both chokes are unported. With the #4s I am averaging 130/10", and with the #5s I am averaging about 170-180/10" at forty taped yards from the end of muzzle. These two chokes have been the most consistent as far as 10" numbers and POI and POA. I have tried the IC .665, KICKS .675 .680 .685, Stardot .668, CNC XXFull, and a Jellyhead 670.