Your 748 powder will be marginal to light them up and that's at max loads. You'll probably get about half to light. You need a powder with a hotter flame temperature. I'd suggest WC844T but that's not something you'll find at most gunshops and it works for tracers only, otherwise it can burn a barrel pretty quick. As far as using them for anything else, they're not worth anything else except a tracer. The bullet doesn't have a lead core and what core that is there is not designed for accuracy. The bullet is supposed to indicate where the general direction of the machine gun fired ammo is going. They can be fun at night but be forewarned, they can easily start grass fires. I've heard both sides of the argument in regards to tracers being hard on barrels. I quit shooting them in anything I intend to keep. YMMV
