This is a street sweeper or you could get it’s baby brother!
Maybe you could chop down a .50 “Beowulf” rifle, or rechamber a smaller weapon for it, or something. (A .50 “Carbon 15” would be interesting…until it tore your wrist off as it punched a “ƒ” shape into the nearest wall.)
I’d just go with a shotgun, myself. (Conventional or otherwise. Probably conventional.)
To bad Birdman’s site isn’t working right - that .50 Browning auto pistol would probably fit the OP’s bill. Either that, or the nuclear bullet firing handgun. 
If I was looking for something that could be carried easily on the person that could actually render an opponent into something that resembles the T-1000 post grenade launcher shot? It would have to be a .454 Casull Magnum loaded with wadcutter “dum dum” bullets. The term “vaporize” comes to mind……
MP-5? Please. For real compact automatic firepower, I’d go with the Micro-Galil or the Micro Tavor.
Submachine guns are neither powerful nor terribly accurate. SEALs would carry those particular weapons for their portability and rate of fire. As they’re in the habit of doing their work in close up and surreptitious manners, accuracy and armor-piercing power aren’t as important as convenience and size.
An M-16 is vastly more powerful and accurate than an MP-5, and you can certainly hide the carbine version under a long coat.
**astro’s ** question is somewhat ambiguous because he does not say, really, what he’s looking for; rate of fire? Distance? Accuracy? Stopping power? It all depends what you’re looking for and plan to do. If you’re raiding a terrorist safe house, you don’t want rifles, you want submachine guns. But if you’re planning on an uban street battle, some more range and accuracy might come in handy. On the other hand if you just want to kill a particular target wearing a vest, a very powerful pistol may be your best bet.
There have been some interesting suggestions, but I’d vote for the M60 .
That’s not a gun. This is a gun. XM134
The MP5 is “sexy” in the sense that it’s a movie star and the SEALs have a version, but as has been mentioned, it’s not all that powerful or accurate. I believe that I once read that it was popular with SWAT teams because the 9mm round wasn’t as likely to overpenetrate walls and such.
The M4 is a good rifle, but still a .223. My personal preference would be something like a .308. YMMV.
I am not a gun expert; merely a Texan.
I thought the OP says concealable? That minigun isn’t going to fun under your trenchcoat!
I nominate this!
I thought the OP says concealable? That minigun isn’t going to fit under your trenchcoat!
I nominate this!
See post #19
D’oh! I could have sworn I didn’t see it mentioned! :smack:
Well, that’s two votes then heh.
And in case anyone is wondering if a full auto 12ga is controllable, check out the videos in the link that Dorjan provides. The gun is fired single handed, on full auto by a small woman (5 foot tall, 99 lb) and so on. Most of the videos just show the gun firing but there’s one showing what happens to a target (wood panel about the size of a man’s torso) from a short burst.
I don’t know if 12ga slugs have any more recoil than regular buckshot but assuming they don’t this thing could make quite a mess out of anything it hits.
My father has a federal firearm’s dealer license. When I was growing up, we had several machine guns for us to play with. One of those was a Mach 10 that fired 19 .45 rounds a second (1140 Rounds PM) IIRC. It was small too. It has to be up there in terms of concealable firepower.
Anyway, the clips we had for it were 50 round clips. We would set up milk jugs full of water with food coloring and just blast away. It was great fun although it is a scary little firearm to shoot (like holding a rocket) but it ran through a clip in about 2.5 seconds. I always wondered what the point was too. I guess it is really meant for wiping about 1 - 3 people that are close together rather than whole villages. I am not sure if a slower rate of fire would be better.
One of the design requirements for the G11 (which, btw, was ordered by that Hitler fellow… took H&K a few years longer to complete the design than they thought it would…) was to put a three-round burst through one hole. Which would sting like the dickens, even with armor on… the first bullet hits and maybe penetrates, the second one hits the first bullet and drives it into the body, then the third one hits the same spot…
An M203 is mighty powerful, though it’s a single shot weapon.
I’d advise standing back before using it though 
Yeah! The little-known but highly lethal OFB 1945LA single-shot pistol. It’s based on the classic Browning M1911, using the same .45 caliber barrel. The round is an exploding shell, small fission bomb with a blast kill radius of 550 yards.
Curiously, the round’s effective range is only 100 yards; the high density of the plutonium/U235 shell makes the round significantly heavier than an ordinary lead bullet. This is also the reason that the OFB 1945LA is a single-shot weapon.
Is anyone else wondering why the hell caseless ammunition hasn’t gotten a lot more popular then it is? And why oh why can’t the G11 finally see some mass production? It looks like a great gun, but its had very bad luck getting picked up by any armed forces
As far as picking a metal stick that does the most damage is concerned I’d have to go with one of those old school WW2 anti-tank rifles - raw power can’t be beat.
The word automatic in the thread title eluded me for the longest time. But if I had to pick the most powerful automatic weapon a man can carry - well I’d work out until I could pick up one of these bad boys