by David Crane
david at defensereview.com
January 21, 2007
This article contains photos (below) of the Transformational Defense Industries (TDI) booth and several KRISS Super V XSMG System prototype weapons at SHOT Show 2007. All photos below were taken by DefenseReview.com, are the exclusive property of DefenseReview.com, and are not to be reprinted or disseminated in any fashion without the express written permission of DefenseReview.com.
The KRISS Super V XSMG System .45 ACP Submachine Gun was hands-down one of the coolest and most interesting small arms at SHOT Show 2007. Yes, the way the gun looks is part of what makes it so interesting. However the gun’s unique operating mechanism is the single most interesting thing about it, and this mechanism is what dictates much of the weapon’s configuration and physical appearance.
In two of the photos below, you can see the weapon’s operating mechanism assembly comprised of bolt/bolt carrier, "slider", and base plate, which are all connected. The weapon operates via delayed blowback. As the round is fired, the…
bolt extension must first overcome an initial shelf. It then travels rearward along an upward-angled channel in the slider which pushes the slider virtually straight down the rod, which compresses the recoil spring against the base plate. After the spring reaches full compression, it pushes the slider back up, and the bolt back forward.
Transformational Defense Industries (TDI) refers to the way the KRISS XSMG re-directs the recoil impulse (a.k.a. recoil forces) downwards as "re-vectoring" the recoil forces. The TDI website further claims that the KRISS XSMG "also reduces muzzle climb by activating a counter-balancing mass that further absorbs shock and re-directs forces that would otherwise create muzzle climb, thus compounding the operator’s ability to consistently put rounds on-target whether through single-fire, multi-round burst or full automatic firing." However, since the counter-balancing mass appears to be the slider, which is part of the mechanism doing the "re-vectoring", it would appear to all be part of the same process. The KRISS’ bolt and slider are supposedly lighter in weight than on standard weapons due to the KRISS’ unique design.
Speaking of unique design, when you look at the weapon, notice that the bore is roughly in line with the trigger and below the grip tang. This configuration should also assist in pushing the weapon straight back upon firing, instead of pushing the muzzle up.
Where recoil attenuation/mitigation really comes into play is on full-auto. The KRISS Super V XSMG’s cyclic rate / rate of fire (ROF) can be adjusted from as high as approx. 1500 RPM (rounds per minute) to as low as approx. 650 RPM. Since the KRISS is supposed to mitigate recoil so effectively, full-auto bursts should be controllable, even when opeating at a very high cyclic rate (at least, theoretically). We’ll see. Like we mentioned in a previous article, we didn’t get the opportunity to T&E the KRISS at the range, yet.
Upon handling the weapon at the T.D.I. booth, I immediately and particularly liked the weapon’s left-side-mounted charging/cocking handle, which is well designed and executed. When not being manipulated, the lever lays flat against the side of the receiver. Pulling the lever perpendicular to the receiver allows the shooter to inspect the chamber (i.e. conduct a "chamber check") to see whether or not there’s a loaded round inside. Pulling the lever all the way to the rear, of course, chambers a round and charges/cocks the weapon. It can also be used to eject a round or empty case (as part of a malfunction clearance procedure). This component is pretty slick (as in cool, not slippery).
However, we found the separate safety and firing-mode selector switches curious. DefenseReview is used to integral safety/selector switches located at the operator’s thumb for quick and easy access and operation. When we questioned one of the TDI staff about it, he said the separate safety and firing-mode selector were done at some end-user’s request, but that they can do an integral safety/selector switch no problem. Defense Review would prefer the latter configuration. Oh, and they still need to design and develop a 30-round mag for it, unless they decide to utilize–if this is even possible–a COTS .45 ACP mag like the Thompson .30-rounder or HK UMP .45 25-rounder. Probably better to just design and develop their own mag.
Having "said" that, the KRISS Super V XSMG System .45 ACP subgun is still under development, so TDI deserves some slack on these points. We don’t yet know when the weapon will go into production, or how it will be priced. If/when it is finally offered to military and law enforcement end-users, the weapon will have to be reliable, durable, combat accurate, easy-to-maintain, and affordable if it is to be successful on the tactical small arms market. Time will tell.
DefenseReview would like to thank Andrew Finn (Senior Vice President), Tom Maffin (Senior Gunsmith & System Demonstrator), and Tim Lindsay (Director, Technology & Engineering) for assisting us at the TDI booth.
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