Ever see the movie Aliens?
The Marine Pulse Rifle has a 100 round capacity to fire 10mm caseless, standard armor-tipped explosive cartridges. And an under-barrel 30mm grenade launcher. Even more impressive is the fact that it's built from an M1A1 Thompson parts set.
Actually, Ed from S.D.Studios was kind enough to send me this image. Ed tells me that S.D. Studios sells licensed prop reproductions from various movies. They currently offer a 24K take-down reproduction of the pistol used by the villain in the James Bond movie "The Man With The Golden Gun" as well as the pistol used by Sylvester Stallone from the movie :Judge Dredd"
They have other various weaponry repro's from these movies, and have an entire line of other newer items coming from the latest James Bond movie "Goldeneye" as well as some going back to the original Bond movies, such as a fully-functional attaché case as seen in "From Russia With Love" S.D. Studios is seeking to do other licensed weapons from other action/adventure movies.
Before you ask, S.D. Studios did seek to license the M1A1 Pulse rifle but were "beat out" by another company. They will be offering something similar to what you see in the photo, but NOT as detailed. They will be reproducing it in resins and plastics with some metal parts. S.D. Studios made theirs out of M1A1 parts to which they attached a replica receiver. A deactivated Browning 870 shotgun is also housed within the lower section under the Thompson barrel. Both weapons will cycle but, intentionally, not fire any ammo. (BATF Rules and such) and they are exact duplicates to the firing versions seen in the movie.
The Thompson in the photo is encapsulated within the green fiberglass shell and is held in place by the screws you see at the front and rear sections. Both the stock and foregrip are removable. They replaced the stock with the skeletonized stock you see projecting from the rear. it extends, and locks, into an open position. You can see part of the stock on the top of the receiver. It will not work with the M1928A1 due to the stock extending over the receiver. The 1928's actuator knob would prevent the use of the stock. this is why the original in the movie was the M1A1.