Fubsy. You didn't say whether for rifle or handgun. Here's one not to use in rifles.
H-335. In a 20 in barreled .308 Win. at high noon in the Nevada desert, the fireball is exremely visable. Muzzle blast is very loud, even with ear protection. At night, my buddy estimated it at 3 to 4 feet in diameter. I gorget the load, but it was near max for a 150 gr. bullet.
Strange thing is it doen't seem to do that in a .358 Win.