Well you can easily go into the .zfs and find a weapon .odf such as the sniper and modify certain things about it such as the speed of the shot, the amount of damage each shot does and the rate of fire of the weapon. The two files you would be looking for are 'gsnipe.odf' and 'snipe.odf'. Edit these with Notepad then put them in addon and there you go.
Regarding the SLF build menu, you would need to find the corresponding file in the .zfs that determines what appears in it and then edit what you like, then put it into addon. I'd imagine that the NSDF Armory build menu file starts with 'av' or something. 'av' being American Vehicle.
If you're creating a wholly new weapon then I think there are certain conditions you must follow when naming the files that make up the weapon. I would suggest that when you're making the weapon you use a pre-existing one for reference.
Sorry I'm not much help but this topic you've created hasn't seen its first response yet even after over two months. Goomba has had experience creating custom weapons, I think he modded a shadower to not need a lock on to fire and then called this modification the 'swarmer'. I think this is based on a weapon from BZ2? I'll try and find him and get him to put across his knowledge on this for you
Oh yeah, and I'm sure you already know this but remember to delete any files you've changed and put into the addon folder and to put back any files that were replaced in the process.
SABRE
