Saw my Uncle do it to show me. He took a shot shell and cut through the hull at the wad all they way around. the wad holds the shell together. He then shot it out of his Ithaca 37. Made one big hole in the paper sack I was using as a target to test buck shot loads. Just the paper grocery sack ( had it side ways on a saw horse to replicate a deer torso) opened the shot part of the shell and there were holes out of shot and the wad and hull together.
We found the wad still in the hull with the crimp open. I would assume that the crimp would open and some of the shot would come out the front as well as the hull and wad would seperate and tumble around a lot of shot as it broke up.
Ralph said it was effective on the doe he killed when he was a kid.
I noticed in the NC hunting rules it said that these shells were illegal to use on game.
Personally I would not do it that way. I think I would go with.
I would use wax, wood glue, or rubber cement in or around the shot in the wad with an over the shot card and load it into the hull after it dried in the shot cup that had the peddels taped together, and remove the tape. That way I would not worry about gluing the wad to the hull and spiking the pressure.
I have seen a guy that shoots targets in the air use a mix of wax and shot and pour that into 45 bullet molds and seat them in 45 Colt rounds. I was a safety officer at the club and stopped him from shooting into the air till he told me what he was trying to do. he thought that with candle wax the heat would melt it and the shot would be released. I thought he was crazy. Tests on paper proved us both right. Some of the shot did sluff off but mostly the wax bullet made a hole and filled in the rifleing of his colt clone.