Contrary to the claims of some, the principle behind "MetalStorm" (MS) is not that new. Anyone familiar with the history of firearms will recognise it as a Superimposed load system with the innovation of electrical ignition. The idea of superimposed loads dates back to at least 1580, when John the Almain refers to weapons of this system, and the idea has crept up again and again over the centuries.
The MetalStorm system does have some interesting possibilities, and I thought I'd jot down a few thoughts.
The Handgun. The pistol illustrated on the MS website resembles a conventional automatic in outline, and the four barrels are part of the weapon. Some other MetalStorm systems use barrels that are part of the reload, and doing this offers some interesting options for a handgun. The pistol would in fact consist of three different elements. First would be the frame, which includes the grip, trigger, barrel supports, sights and firing mechanism. Next would be the barrels, each resembling a tube with a breech cap. Each barrel would be loaded with a single cartridge. The cartridge would be several inches long and contain an alternating stack of bullets and propellant charges. The loaded barrels are used rather like the magazines of a conventional arm:- you carry several and insert a fresh one into the frame whenever you wish to reload. I can see the barrels being about the same length as a conventional magazine and fitting in the same pouches. Suppose as a standard combat round we select something of similar size and weight to the proven .45 ACP round. Since the MS bullets don't need to fit in a grip we also have the option of using even larger calibre bullets. .476 rounds were popular in the 19th century, and the double barrelled version of the Lancaster pistol was available in .577 at least one of these guns was converted to fire 20 gauge shotshells. There will be times when a shooter might wish for a high velocity round like the .357 magnum or 7.63mm Mauser for long range or high penetration shots. The bullets loaded in a MS barrel needn't be "pistol" bullets. These rounds could be pointed boat-tail rounds. The Whisper® series of rounds have proven that these can be highly effective in pistols such as the Thompson Contenders. A MS pistol could do the same but would be multiple shot.
I see no reason why a MS pistol needs a barrel group that revolves, nor do I see why it should be like an automatic in outline. A more suitable configuration would be a four chambered weapon similar to the Victorian Lancaster pistols. By having the barrel a part of the reloading unit you have the option of "mixing and matching". You may load two chambers with .45 barrels for general use, one with high penetration .30s and the fourth with a less-lethal loading. The MetalStorm website suggests "mini-beanbag" rounds, but other options would include charges that fire a blast of OC powder, mini-sticky shockers or some form of Taser barrel.
Four barrel Lancaster with a Tranter style double trigger
What were the barrels on a Lancaster pistol would in fact be barrel shrouds and chambers to hold the reload units, and would be made of a light alloy or polymer. The space in between the shrouds would be used for an integral laser aiming module. For a police weapon this section could also hold a miniature digital gun camera. I'm reminded somewhat of Judge Dredd's pistol in the comics. This had a semi-circular dial to select bullet type. It also had a viewscreen on the back. I could never work out how the optics looked down the barrel- on the MS pistol we are considering they would be between the barrels. Like the best duelling pistols the grips of the MS pistol could be set to suit the individual for optimum pointability. I'm envisioning a four barrelled weapon for "Duty" wear, but a double barrelled over/under weapon could be used for concealed carry applications. There is also the possibility of mounting a single barrel in a wand or kubotan-type weapon. A nine barrelled weapon could replace the assault pistol or machine pistol.
The Lancaster was a break-open weapon. A better option maybe a weapon with four gate loaded barrels. When an eject button is pressed the gun either ejects any empty reload tubes or those that have less than a certain number of rounds left in them. The gun could also be programmed to eject empty tubes as the last rounds is fired, if this is what is desired.
There is no reason that the barrels need to be above the grip. A "T" shaped weapon with the barrel projecting between the fingers is possible, and such an arrangement would exhibit very little muzzle flip. The Disney movie "Black Hole" had a laser gun with one barrel above the grip and the other below, rather like a "U". In an MS weapon of this shape the flip of the upper barrels would be canceled by that of the lower.
The electronic fire control offers some interesting possibilities too. The MS website mentions pistols that can fire "double-taps" automatically. The gun could fire the LLW barrel first, then automatically switch to .45 should a follow up shot be needed, or the gun fire both a .45 and .30 at a target who's protection level is unknown. The electronic trigger system is another interesting feature. One could set the trigger pull to be as light or heavy as one wished. Better still, this setting could be changed at the touch of a button. You could have a fairly insensitive setting for carry which switches to a lighter pull once the first round is fired. An even more sensitive setting could be selected for target work.
Metal Storm Assault Rifle I think a multibarrelled MS rifle would not be that practical for an infantryman. The configuration I see working best is something like the H&K G11 in outline. The magazine is a cylinder of about 12" length containing several stacks of rounds around a common axis. This inserts into the top of the weapon just ahead of the butt-plate and rotates to align a fresh stack with the barrel as each is emptied. Standard fire mode would probably be a high rate of fire two round speed burst.
The round used would be ballistically similar to the EM-2 .280 round (140gr 7mm at 2529-2749fps) and there would also be a machine gun varaint. Performance of this round should make it unnecessary to have other machine gun calibres under .50. The weapon would have standard assault rifle features such as mounting points for DGLs.
Aircraft Gun Pod The other application I like the MetalStorm for is as aircraft armament. The MetalStorm website has a video of an aircraft flying over targets and attacking them with downward firing computer controlled MS pods. That maybe a good way to attract SAMs and triple A and may be more workable if the pod is part of a drone launched from an aircraft. I'm more interested in forward firing pods that can be used for close air support to support ground troops when there is no time to program a computer. These would be rather like FFAR rocket pods, but firing bullets and shells instead. A conventional aircraft gun pod usually only carries a weapon of one calibre. A pod of metal storm barrels offers the option of having barrels of several different calibre, and the ratio of these varied to suit the expected mission. An aircraft might mount .50 barrels for anti-personnel use, and 30mm ADEN equivalents for heavier targets, with a few high velocity 25mm for attacking AFVs. Scrapboard reader Peter Tecks has pointed out to me that a Davis recoilless system using sand or water countershot would be compatible with MS technology. A gun pod could contain a mix of MG calibre conventional tubes and recoilless larger calibre.
Canister Barrels Long before I head ever heard the term "MetalStorm" I proposed that a useful variant of Disposable Grenade Launcher might be a tube containing several superimposed shot loads. Mounted beneath a rifle or SMG it would be a useful system for blowing off door hinges and locks. Mounted under a Grenade launcher or Blunderbuss it would provide a close range defence that brought sufficient time to reload the main weapon with canister. Used on its own such weapons would provide useful "whippet" guns. Such a tube may also use the shot-spreader technology used on some Franchi shotguns.