: Probably better to put the charging handle on the side rather than the top.
: Either side is fine; FALs and G3s have it on the left, while AKs have it
: on the right. Make sure to keep the ejection port on the right side. A
: second trigger for the grenade launcher is probably the way to go, a la
: the M41A.
Here is my interpretation for a realstically plausable version of this weapon:
http://www.moonbase-industries.com/MV/ma75_reload.avi
It was for a HL2 mod that never took off, but we got a few cool things done while it was in production.
I came to the same conclusions that Bob-B-Q had for the most part. Though, after looking at the sprites and a few other drawings I could find, I came to the decision to make it a bulpup style rifle (magazine placed behind the trigger) smilar to how Bungie made their main rifles in the Halo games. There just didnt seem to be any other place for a conventional style mag.
Though, for the shotgun, I wouldn't design in an external hammer(s). Clearly in the game sprites there are none, and most modern shotguns don't either. Though I suppose as far as making it realistic... no matter how you slice it, a level-action double barrel shotty is going to be a pretty thin stretch.