After having Hans Vang Comp and port my 870's 18" Cyl barrel the results with Federal 2-3/4" 00 Low recoil Tactical Buck are as follows:
( Groups measured center to center of the holes farthest apart )
7 yards Just under 1.5 inches
10 yards just under 3.5 inches
15 yards 4-3/4 inches
I also found that Federal #8 2-3/4" target load patterned at less than 1/4 the pre VangComp pattern size! VERY impressive. Both recoil and muzzle rise were considerably decreased as well.
How does this compare with you other VangCompers out there?