Good job Dave. At first I thought BSA stood for Boy Scouts of America, though. But I don't know who will be trying to make a SCAR-N with the longshot out. It seems capable of doing anything the SCAR-N can.
Are you making something like this craptastic ms paint picture?
Black= Rf20 White box= air source Red= turret Grey= hopper Blue= piston
Sorry for the poor quality, I'm a little tired. Cole, if this is anything like what your doing, you should be able to recognize it. If, not please explain what you are doing or post a picture please.
There's also chiefthe (and probably some unregistered readers) who is a Nerf engineer and is kind enough to answer questions for us about new guns and on one occasion I remember even gave us pictures of the Mav before it hit shelves.
A bit off-topic, but there was a preview of the mav in the N-strike DVD.
Nobody will give you the right answer if you ask the wrong questions. When you say "cartridges" you mean clips, or magazines. I don't think that they knew what you were talking about.
Edit: Rethinking this, I think that they thought you meant "dart" when you said "cartridge", as many people do call nerf darts "bullets".