Most of them have a standard set of bones defined in the art section. Like the humvee:
Code:
WeaponFireFXBone = PRIMARY Muzzle
WeaponMuzzleFlash = PRIMARY MuzzleFX
Or on the missile defender:
Code:
WeaponMuzzleFlash = PRIMARY MuzzleFX
WeaponFireFXBone = PRIMARY Muzzle
WeaponLaunchBone = PRIMARY Muzzle
WeaponLaunchBone = SECONDARY Muzzle
So Muzzle is usually the one you need, but it can change depending on the unit. And you always need to say WHICH muzzle it should be, even if it only has one. So you actually need to put in Muzzle01 or Muzzle02.