Following the Unique-substitute discussion with interest.
Up until a few years ago I shot a lot of shotgun sports and reloaded all my ammo, buying my powder in 4-5 pound jugs. As a result I find myself sitting on a ton of Clays, Universal Clays, Red Dot, Green Dot, and Unique that now only gets consumed in tiny amounts for .32, .38, and .45ACP. It should last me 'til the end. But what if it doesn't, and I then need to consider alternatives? Knowledge is a good thing. What I really should do is convert my stash of shotshell primers into pistol primers or it'll all be a moot point.
