I heat it a couple seconds with the electric heat gun on low, then press the cup over the ball end of a ball pein hammer. The hammer I use is an antique brass, medium size one. Easier on the hands when doing a whole bag is to put a nut driver into the shot cup to press the wad over the hammer held in a vice.
Edit to add, the SP-16 wad doesn't flare as well, a bit short on cup walls for that to work.
Last edited by Ole_270; 12/06/21.
