I just bought a used barrel for an old Mossberg 500 20ga that came with an improved cylinder choke in it. The barrel says it takes Accu Choke tubes, as expected.

The problem is that the choke tube's extended portion bottoms out before it bottoms out inside the barrel. There is an 1/8-1/4 inch gap between the barrel's shoulder and the inside edge of the choke tube. This makes a ledge that I am afraid will hang up wads.

This seems like a big problem to me, like someone found a choke tube that has the correct threads but not the correct length. Is this possible? I guess I just want verification that this was not a designed in ledge meant to strip wads or something.