Hey guy's new member here. Lot's of great ideas here.
I've been making "more lethal" rounds by trimming the ring, emptying birdshot, filling with BB's and capping with hot glue. The wax technique scared me because it melts at around 100 degrees but hot glue doesn't melt until it gets to 125 or so. Anyway, it's the cleanest method I found because I use the glue gun and if it's rough on top I can smooth it with the side of the glue gun tip. I also made some solid slugs out of glue and birdshot that put quarter sized holes all the way through a regular (thick), phone book, with low brass. I'll have to try some of these also but I think I'll stick with the hot glue for capping them, plus it's cheap.