Quote Originally Posted by Beat Trash View Post
This is our issued duty round for shotguns. At 5-7 yds, it's very hard to tell the difference between OO buck and slug, using issued 870's with cylinder bore chokes.

We have over 1,000 officers to qualify with shotgun, using about 20 range guns to do so. No signs of the type of patterns you are describing with cylinder bore 18" Remington's. Is it possible that some part of your screw in choke is catching on the wad and stripping it?
Wondered about that and thought the thread could have been cut off center, but I can feel that the "inlet" end of the choke wasn't overlapping in to the "outlet" end of the bore. I don't think it is this particular ic tube since nothing looks/feels wrong and the patterns are consistent with various loads. Doesn't really feel like the choke gets tighter when the patch passes in to it when cleaning either.