Projectile modding

Hi guys,
I'm modifiying another mod (just for me!) and
I can't figure out how your projectile system is working. A script?
How are the entrys in the weapon .tweaks linked tho the .cons in the projectiles folder.
I don't get it 'cause when I made a projectile .con and placed it in the projectiles
folder of the other mod, and changed the entry in the tweak to then ame of the .con,
nothing happens ingame, there's no projectile anyway. Can you help me?