Here's an article that I think all the gunbunnies out there (you know who you are) will enjoy:

When Seconds Count: Idaho Integrated Breaching Shotgun

It's a prototype underbarrel shotgun developed by the US Department of Energy's Idaho National Engineering and Environmental Laboratory.

Read and enjoy.

That's not new. The French produced an underbarrel shotgun for a pistol sold to the Union during the Civil War.

Looks flash, though.

Under barrel shotguns aren't a new concept. There's an m16 variant known as the masterkey that incorporates an underbarrel shotgun.

One Random Source of Many: Link

Forgive me if this is a silly question, but why is this coming from the Department of Energy?

~J

That's enough reason for them to be obtaining and deploying them, but I wouldn't think that they'd be developing it...

~J

Ancient History:

I may be mistaken, but I believe that the weapon to which you refer is the LeMat revolver, sometimes known as the "LeMat Grapeshot revolver", which was used by CONFEDERATE officers.

Designed by a Confederate officer from Louisiana, the LeMat was a nine-shot single-action percussion ("cap-and-ball") revolver of approximately .42 caliber, with a secondary smoothbore barrel of approximately .69 caliber (roughly the same as the obsolete (since the 1920s) 14-gauge shotgun bore size) which also served as the cylinder's axis pin.

The LeMat design featured a pivoting nose on the hammer: in its normal position, it fired the chambers of the cylinder; moved into the lower position manually after cocking, it was ready to fire the shotgun barrel.

The weapon was a favorite of such noteworthies as General P.G.T. Beauregard, and Major Generals Richard Anderson and J.E.B. "Jeb" Stuart.

Here's a little more information about it: http://www.pride-net.com/january/1998/civilwar/lemats/htm

--Foreigner

Ah, I must have confused it with their Union revolver, which had the .50 caliber underbarrel and 10 .30 caliber rounds on the upper. My bad.

Ancient History:

Could be.

Then again, it's just as likely that there was a Union counterpart to the LeMat of which I was not aware.

--Foreigner

Ya know Kage, I had a similar reaction.

However, I'm going to guess someone who felt the need or perhaps believed in the project decided to bypass the traditional outsourcing and make use of in-house resources.

Just a guess.

-Siege

Unless they went under DHS with the whole reorganization, NEST is under DOE.

IMO, this thing is a solution to a problem that doesn't really exist. Having a guy with a shotgun pop locks or hinges doesn't really waste any time at all, as long as everyone is aware of what's going on. No one needs a longer barrel on an underbarrel shotgun, nor do they need a bunch of rounds. They're primarily used for door breeching, which generally requires three rounds.

It looks also pretty cumbersome, especially on that freakin' MP5 (mostly because of that huge box mag sticking out of it). I don't think it will get very far.

KAC's Masterkey was a better deal, IMHO. Hell, having a Serbu Super Shorty as a backup would be better, I think.

....I wonder what the Super Shorty's stats would be for SR...Although a Roomsweeper is of similar concept.

Except the roomsweeper holds a crapload of ammo, and uses Heavy Pistol ammo, I think.

I have it under the nonexistant weapons list in my games. Along with the AVS! Oooh!

Yeah. But I want a shotgun with Heavy/Light Pistol conceal, shotgun damages, and is a pump/semi-auto, not a fraggin' Eichiro Hatamoto I.

Nothing quite beats a brick of C4 for when you don't care what's behind the door or how big your entryway is, though.

It's either that or using small explosive charges on the hinges -- but I think the logic runs, "It's easier to take advantage of current training to use shotguns rather than teach them to use small amounts of C-4."

-Siege

...Stock? What stock? All it has is a foregrip that folds...And I think the conceal would be a LOT bigger judging the size of the pistolgrip compared to the size of a human hand. And didn't it say three shots in the magazine as well as a fourth in the chamber?

...Sorry to be a nitpicky barstard.

It is easy to misjudge the proper amount of C4 to use. By the way, personally, I've never seen anyone use C4 to do the doors but I've seen people use Detcord.

Stock? Ack! Meant to say foregrip. On the concealability, I looked at a couple pictures and it seemed to be roughly the same size as a lot of submachine guns so I put it in that general category with a rating of three. As for the magazine size... there seems to be some disagreement between sites. There is a 20 gauge version of the weapon though so that might be what you mean.

Plus since the thing is so small, I'd also probably consider hitting it with an increase in recoil penalties, taking it up to a +2TN after the first shot rather than the normal +1. But since it's a SS gun that's academic, unless you play it that pump-action shotguns are classed as SA weapons.

Makes sense to me.

...Erm, shotguns already suffer doubled recoil with the exception of the Roomsweeper (depending on your nitpicking)...And most SMGs I think have a conceal of 5, usually 4.

But...Bleah.

I thought that was just for firing in burst or fully-automatic mode? 'Cause if not, well I've been lucky with past GM's then I guess. And on 5 or 4 ratings, I usually use Raygun's general scale of things since that seems a little less broken to me.

No, they have doubled recoild for uncompensated burst fire.

Like, a shotgun with 2RC firing burst would negate the first 2 points, but the 3rd would be doubled to +2 recoil, because its not compensated.

Ahhh, okay then.

Notice that it needs to be pump to feed the door breaching rounds, they are too low pressure to work a gas operated shotgun. This is why some combat shotguns will switch from semi to pump, so you don't need another weapon to fire 'special purpose' munitions.

The breacher rounds fire a pellet of powdered metal, you fire the shotgun somewhere between 1-2 inches to contact with the door (pointing at the lock/hindge) and there is not too much danger for anyone on the other side. The main advantage of this system over explosives: it's cheap, you don't need too much additional training, and it's less dangerous to people on the other side of the door.

To recap what Bob said, and pimp Ray's site, here's a couple examples of a convertable shotgun that's useful for situations like that, plus lockbuster rounds and associated barrel accessory.

This seems like a complicated solution to a simple problem.
First, don't carry a breaching shotgun, just carry a shotgun, period. Load a Mossberg 590 with 00 buckshot, blow the door, go through the door, blast the crap out of anyone on the other side of the door with the same weapon. Standard movement procedure anyway is the first guy in dodges right and the second guy in dodges left, so you'll have an assault rifle in there no matter what.

Or just carry breaching charges.

I've never understood the unbarrel shotgun. What do I need a shotgun for that the assault rifle won't do? The only application I can see is loading the shotgun with nonlethal rounds and the rifle with lethal.

Although the article's mention of a shotgun redesign that achieves higher muzzle velocity by more efficient use of gasses is intriguing.

Zen, you will note this wasn't a military design program, suggesting civilian LE applications.

Which means you can either:

1) train SWAT units to use breaching charges
2) risk a major SNAFU with explosives

-or-

Use existing training and equipment that also offer minimal risk scenarios.

-Siege

Also note that in poorer places, 'regular' officers might be the ones doing the forced entry, which would mean refresher training in explosives every 6 months for several officers, or just 1 hour more range qualification, showing door breaching techniques.