17DE,
Sho-nuff, a double action. And Moon Clips are the best way to approach the problem. I am head spacing each cylinder, so you can single shoot, so moon clips won't be absolutely necessary, but I am cutting out the cylinder for moon clips anyway, they are the best speed loaders too and moon clips store ammo very well..A semi-auto is pretty much out, the mag well through the hand would be nearly impossible to hang unto, unless you were as big and had the hands of Big Foot. Of course a semi-auto could be made much like a Broom-Handle Mauser (
http://www.northwest-denture.com/mauser1896/) and that's not a bad idea, but it's not a pretty weapon and sales go best to the pretty guns,right, but hey, you and I would love them..A Broom-Handle 450 Bushmaster, using M16 mags, has a ring to it doesn't it? It'd be an expensive rig, but Holy Cow!! HEY, come to think of it how about a,
http://www.bushmaster.com/catalog_carbo ... 15P97S.asp , and I have made them with NO Buffer Tube and with an optional; side folding stock..Humm