Is there anything 'special' you have to do to SM's??

[BotHunter]

Arg! I've just about given up trying to make this work!!!!

so I have been playing around with the projectile files, Making a gun fire a certain thing. But I've run into a problem with the .SM files. If I make one in Gmax and save it, It wont work in BF at all (As a projectile file)(The gun fires but nothing comes out) I save the LOD like your supposed to, but it just doesn't work!!! I know its the SM file because if I tell the projectile file to use something else, It works just fine.
This Problem also happens if I simply copy a SM file that works and then name it something else. PLEASE HELP!
Thank you!!

[Swaffy]

Make sure you have the correct collision mesh with material IDs. You also need to use the correct coding for the projectile with working material IDs in that too. Try comparing it to existing projectiles.

[BotHunter]

But why would it not work when I copied an existing one??