I use a BPI X-Stream, plastic X insert, in the WS-2 barrel of a 12 ga. M-21.
That's choked .015, and is way too tight for the second shot at skeet.
I load 1 oz of 9's with a 1 1/8 oz wad and just push the X wad in the shot. I've been told to put the wad in first and then add shot over it, but I'm not taking all day to load a box of shells. I use a Grabber.
It works fine. Incomers at 1,2,6 & 7 think it's a skeet choke.
One thing I quit doing is removing the petals on 20ga wads to make spreaders with the X-wad. The barrels leaded so bad, I was afraid of causing a lead obstruction with the sheets of lead the shells left on the barrel walls. No more of that.
