Well the Tempest .670 was a miserable failure, at least in my 935. I fired two Heavyweight 3 1/2" 1 7/8 oz #7 and at 40 yards got 108 and 78 in a 10" curcle at 40 yards. Large paper so I didnt miss the core, there was no core. Shot all over the place. The wad flew nearly the entire 40 yards and dropped just in front of the target. I have no idea why this combo would be so bad.