Surfing over at the Smallest Minority, I stumbled across this article about the garage gun industry in Pakistan. The weapon pictured is the M3 submachine gun, and looking at the picture brought back memories of being a tank commander in the mid 1970's. I shamelessly stole the picture from the Smallest Minority.
That is the whole thing. About as basic as a firearm can get, and it only fires in full auto, and it fires that big ole .45 ball ammo, the same stuff that rides in your 1911. You can see the full size picture here.
The only problem I ever found with the M3 was that it got hot after a hundred rounds or so. Wearing gloves while firing it was a good idea. Wearing gloves and being sure the barrel was securely screwed to the receiver. Launching your barrel downrange was considered poor form.
The M3 was the first weapon I qualified with after I got my commission. The course was fired on a fifty-meter pistol course with half-sized popup silhouettes, and it was a frigging hoot. The targets would pop up and we would hammer them down in a burst of .45 ACP. The M3 was the damndest weapon I ever saw and I remember thinking I could replicate it in my grandfathers machine shop. I had to buy one after my knuckleheaded driver ran over it with my M60A1. After depreciation, I wrote the government a check for $3.21. An M3 was a bargain in the'70s.
The Guide Lamp division of GM made a gazillion of these things during WWII and charged the gummint about $21.00 apiece for them. Quite the frugal weapon for the discriminating tanker. I bet the guys in Iraq could use a couple of crates of them for clearing rooms. I know that the M3 would be the cats whiskers in an urban environment.
Toss a WP grenade into a room, then follow it up with a burst of M3 fire. Extremely effective, as long as prisoners weren't a criteria.
I wish I had one hanging in the closet.