I talked to bob the owner of ACE LTD at length about his Bulpup and I fitted a 30 rounder into it and they fit in no problem I found it even more ergonomic with the 30 round magazine installed due to the curve, also both of the forward pistol grips can rotate left and or right outward away from the centerline as well as moving the pistol grip forward if needed, So the magazine will never be in the way. It uses a stock AR Lower, Upper, bolt, barrel magazine etc. The carrier is shortened and uses a piston and spring like the Para FAL. Another issue was the left hand shooter, for them the Stag arms upper and lower can be used to make a left hand bulpup out of it. It is still in the development process so it will look differently when it is ready for completion. I talked to him about possibly using his own extrusion for the top and making the left and right rails removable as well as what kind of covering to put on the cheek piece, foam is easy on the cheek but will get tore up quick in the field. The butt stock part very likely will be injection molded plastic. A QCB was also talked about some. It could be included into the system as well. I've personally never like the design of bul-pup's but this one handled better and felt better then any other one i've used even the Styer AUGs that I've shot. 762