Thing would need to be belt fed to be of any use. Aside from the multi-bore design, I only see this as upping the ante on failure points.

The Army is either going to test this and say, "Thanks, but no thanks" or they are going to ask for changes that he balks at because this is his baby. Then, if the Army is still interested, they will ask for a few companies to test out the concepts they like that aren't patentable and this dude will be steamrolled by a large manufacturer because something like a multiple-bore system isn't exactly a new concept and he won't be able to fight it in court.