I've been interesting in a CQB-length MPS AA12 for years now, but the biggest issues are the practical ones.
If they make it GBB, you essentially have a very large pistol. However, it's probably closest to a realistic AA12, especially if you could work it to fire multiple rounds.
If they make it an AEG, then there's no point. Too bulky. Sure, it looks cool, but whats the point?
If they make it shell ejection, can you imagine the number of shells you could go through? And chasing all those shells?
Maybe you could base it off the TM system, but those have no provision for automatic capabilities.
If someone could do it right, I'd be interested. Until then...
The King Of al-Talk. Hey, at least I'm not a troll.
My dog wouldn't know what to do with a duck if she caught it, but she's cute. And hates Mexicans. +1!