I recently have delved into reloading 12 gauge shells. Besides building standard loads for birds and bunnies, rolling my own has allowed me the opportunity to experiment with custom loads. As a side note – any shells that fail to crimp properly spill shot. In these cases I dump the shot out and set the blanks (a primed powder charge behind a plastic wad) aside for my son to use. These loads have zero recoil but fire the plastic wad straight through card-board boxes at 15 yards allowing target practice and the ability to learn safe shotgun handling without the fearsome recoil of the mighty 12. The targets look like you have been shooting slug loads.
The first experiment I conducted after learning to load standard loads of birdshot was to build half power loads with a full measure of powder and ½ the shot charge. These let my wife and son use the shotgun in a perfectly lethal manner for both targets and eventual hunting use without the full recoil of a 12 gauge.
Well last night my son (10) decided that he wanted to reload. So we loaded up 25 shells with ½ the shot recommended and 25 blanks loaded with packing peanuts in a plastic wad over a normal powder charge. Then we recruited my normally non-shooting wife and went outside in the gathering dusk and had fun knocking down pyramids of tin cans first with the wadding from the blanks then with the ½ power loads.
A good time was had by all made possible by my little Lee Loader and an antique side by side.