Anyone have any good recipies for a flash grenade? There used to be a thread on this, but it was deleted when we got hacked.

70/30 KClO4/Al in a cardboard casing.

Newer style commercial flashbangs are a reusable casing (believe it!) usually made of steel or aluminum with a bunch of holes in it. Inside is a dispersal and ignition charge, usually a low explosive that even a mook like you could get his hands on: Black powder, smokeless, or similar. The "charge" itself is powdered aluminum which is shoved out of the holes in the casing when the small charge inside goes off, aerosolizing it and mixing it with oxygen in the air, at which point the residual burning bits (technical term) from the low explosive charge ignite the aluminum and it all flashes over at once, resulting in a big flash and a big bang but with minimal chance of shrapnel projection. All of the engineering goes into making sure that the casing and charge disperse the aluminum powder properly. Any idiot can make aluminum powder at home: Shredded aluminum foil (try an old blender) milled in a ball mill for a couple of days is usually more than fine enough.

Older flash bangs involved a casing that wouldn't present much of a shrapnel risk (cardboard or plastic) and essentially a fuckton of run-of-the-mill flash powder inside. The trouble with these was that they tended to A) throw the fuse assembly with considerable force, and B) set things on fire.