Actually I think it may be the "ObjectTemplate.fireInCameraDoF" command that does that. If you use that on aircraft with mouse lock enabled, you can aim with mouse lock by rotating the camera. That's why certain helicopters in DesertCombat like the little bird can aim like this while others do not.
If it's turned on, the position of the projectile (that is the projectilePosition and or addFireArmsPosition settings) become linked to the camera. I checked some of the code and it appears that most if not all handweapons have this code enabled. Thus the projectile position is relative to the camera and not mesh. Handweapons are handled differently then fireArms due to the host meshes being tied to the soldier skeleton which animates. So I don't think projectiles will fire out of the correct location on a handweapon if the fireInCameraDoF command is turned off or omitted.
For example I needed to add this command to a special handweapon that i use to detonate mines with since the projectile wouldn't fire in the correct place.It fires a special projectile that has armor turned on and a mass higher then the mine's they are detonating. Projectiles can cause other projectiles that have proximity fuses to detonate so long as the projectile that you want to trigger a proximity projectile explode from has armor turned on and has a mass higher then the target projectile. You don't need to give the projectile a collision mesh, but it does need to have collision physics turned on, otherwise projectiles with proximity fuses won't react to them. This holds true to PCOs, if a PCO doesn't have collision physics turned on, it can't trigger landmines. Also any object you want to trigger a landmine with must have a mass higher then the landmine type projectile. This is how I got my RC minitank vehicles to not trigger landmines in my mod. They have a lower mass then the landmine. I gave the landmine a mass of 600 or so. All my normal vehicles have mass'es higher then that. But my minitanks do not. Thus they can run over them without detonating them.
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