I haven't seen a post for this yet, but Armorcast, has metal cinematic effects( muzzle blasts, missile launches, laser blasts, PPC shots) that they make for Warhammer 40K. It also works very well, as I've seen in some Camo Spec photos, and also tried myself on battletech mechs and vehicles. For muzzle blasts, it's best to use the medium, or small muzzle blasts on mechs. Anything larger will look out of scale with most mechs, and tanks. here is there link:
http://www.armorcast.com/
