So, here is what I created: A simple 40mm grenade launcher. It uses the Combat Shotgun as the model. It does however use the "Bait Grenade" projectile animation (not sure if this is a Calibr ammo type or not). The ammunition it uses is Missiles (of which I've renamed 40mm grenades) I have also added an ammo box with 20 of these grenades. Both items can be found in the PC's Megaton house. The launcher is in the bedroom on top of the filing cabinet and the ammo box is in the same location between the bed and filing cabinet on the floor. Hopefully I have set the ammo crate up correctly and it should respawn the ammunition.
All that I ask, is that some of you DL my files to try them out and let me know what you think. Hopefully the gun isn't too under or over powered. Also, if someone would like to reskin the weapon that'd be great too. The other thing that I ask is that if you do make changes to them please let me know and maybe allow me to add them to my file list.
Again, it is my first mod and may not be the best but hopefully it'll be something someone likes. I'll keep on making new things and hopefully I'll get better.
The files can be downloaded here: http://fallout3nexus.com/downloads/file.php?id=11246