Indian Creek makes a .665 and a .675 for the Invector +. My BPS which has a 26" barrel patterns the MagBlends better w/ the .675 and the 6's and 7's better w/ the .665. Interestingly, my gun patterns only slightly better w/ the 31/2" shells vs. the 3" in the Hevi-13 gold hull shells with a lot less recoil with the 3" shells. Both the 3" and 31/2" Hevi-13's produce impressive turkey killing patterns (> 100 pellets in 10") which hold-up out to 50 yards which is the furtherest which I have patterned both tubes.