BP granule size, what is optimal?

[Ubehage]

I'm about to make a new batch of BP, intended for lift and small salutes.

For that purpose, I would like my granules to burn as fast and violent as possible. To my experience, it all comes down to BP-grain size:

Small grains gives a more steady burnrate, where larger grains have more surface to ignite at once.

 

So, I was wondering if anyone here had experience with the optimal size for BP-granules?

[BurritoBandito]

Actually, the smaller the grain size is, the more surface area that's exposed at once. Meaning a smaller grain will release its energy more rapidly.

[FlaMtnBkr]

That is true to a point. Too small and the spaces between grains that are the path for fire get choked and slows down.

 

I have never experimented with grain sizes and speed but I would think -12+20 mesh would be a pretty optimal cut.

[Niladmirari]

[schroedinger]

For what you want to do, i would take 20 to 40 mesh.