I have a better load now. Bore rider size 12 gauge slug with gas check on top of powder and Cork discs on top of the gas check and then place the slug on top of the cork discs. I made my cork discs from cork board I purchased at staples 4 pack for 14 bucks 12x12 boards and I get over 280 cork discs from each board. I cut them with a socket I honed into a cutter. Smack them out with a hammer on a stump. I have recovered the gas check and the cork discs and the discs are not charred and are much bigger diameter ..seems they also act as a gas seal a bit. I tried regular wads of a few different varieties but my groups were tighter with the discs and gas check. You can place all this together by hand NO PRESS needed. But I do use one tool that is excellent a 4 Pin roll crimper I suppose any roll crimper will work. Now You DO NOT need a vise to hold the shell during roll crimping. Just fold up some sandpaper and hold the case in your fingers. Or rubber gloves that have some grip. My hands are very dry and holding or grabbing things becomes difficult for me. Here is another picture of the loaded rounds and notice the gas check I made from a regular bird shot wad and the cork discs. I have the larger diameter recovered discs to the left with the recovered gas check. next to the red slug. Blue Dot powder is what i was using for this load. I made some more for more testing. Be aware if your barrel is skinny at the muzzle a bore rider slug depending on diameter and hardness and shape can swell the end of the barrel. Like shooting the old pumpkin ball 12 gauge slug. Happy shooting.