Oftig is very much correct about the antimony granulation. I have successfully made the mix many times...but the times it failed were due to the antimony granulation. The airfloat stuff wont work, i got some 325 mesh and it wouldnt work, sometimes would fizzle but thats it. Even tried it with chinese needle (about 200 mesh)...same thing. Both from a fireworks supply company. Then got a slightly larger granulation from a chemical supply company and still didnt work. I ended up mixing a 1:1 ratio of the chinese needle batch and the chemical supply company batch...mixed it up into FA-42 and it worked amazingly perfect. I had read the same info mr.Oftig posted and it made sense...the granulation ratio was extremely important for success.