Deconstructing the KRISS Vector submachine gun

     The KRISS Vector is to weapons what the M16 was to lever-action rifles. Lever-action rifles were a far cry more efficient than, say, muskets. Am I exaggerating? If so, it's not by much. The KRISS Vector really is the next step in weapon design evolution — and I expect that some day, in the not too distant future, the recoil-absorbing design they've developed will find its way into other arms.

     So, what makes the KRISS Vector so radically different? The engineers at Transformational Defense Industries (TDI — owners of the KRISS system) didn't start out using the "same old-same old" recoil-absorbing system (i.e. a bolt in front of a spring that travels straight back and forth). Instead, they put their minds together and came up with a way to redirect the energy of the recoil down. This means they had to redirect that energy in front of the trigger group, or the downward energy would only put more torque on the wrist. Let me explain.

     When we shoot, our weapons either recoil up in an arc, or they recoil with a twist if they have rotating barrels. For centuries we've ridden the impulse of recoil as our weapons rose up, and we muscle them back down to proper aim on the target. Recoil absorbing systems absorb much of that energy so we can get back down on target faster.

     When you think about a weapon's movement in that recoil arc, you know that the pivot point for rifles is our shoulder, and for handguns it starts at our wrists. The recoil arc center rotation point is behind the weapon's trigger group. What if the recoil energy could be directed down in front of the trigger group? What effect would that have on how the weapon recoiled? If you're someone who really enjoys shooting, the answer is actually a little amazing.

  1. Moving the energy down in front of the trigger group means that the recoil arc center rotation point is in front of the trigger group. This translates into less energy being absorbed by your wrist/arm/body.
  2. Moving the energy down in front of the trigger group also helps offset the recoil energy that is trying to push the barrel up, resulting in an overall reduction of felt recoil or muzzle climb.

     The secret of TDI's success is a block that exists in the KRISS design. This block exists in front of the trigger group and has a V-shaped notch in it. As the bolt moves backward, arms on the back end of it engage the V-block, and the energy of the bolt is turned to move down instead of back. As complicated as it may sound, if you look at the diagrams you can see what I'm describing.

     When I first saw the KRISS Vector I thought it looked a little strange. In fact, my first description of it accurately mimicked my perception: "broom-handled Mauser meets Star Wars."

     For those of you who can remember them, or have seen pictures, the broom-handled Mauser had its magazine in front of the trigger. The handle was very slender, like a broomstick. The result was a handgun that was kind of long for its relatively short (4-inch to 5-inch) barrel.

     In today's submachine gun market, having a short barrel in front of a longer weapon is not uncommon. If you look at weapons currently dominating that market, a 5-inch barrel isn't a surprise. The rest of the length of the weapon is usually comprised of upper receiver, lower receiver with trigger group, magazine well and whatever stock assembly you're using. That is basically the same configuration as the KRISS Vector — except that they've also put the recoil absorbing parts in front of the trigger.

     Early prototypes (which I got to shoot on a cold February day in a mix of rain, sleet and snow) were a bit heavier than current production models. Without a stock or magazine, the current KRISS Vector weighs just a hair over 5 pounds. It is 16 inches long with the stock folded, and if you fold the stock out you get a long — and note the sarcasm here — 24.3 inches.

     A few other popular characteristics of the weapon are:

  • It is a .45 ACP caliber weapon. While 9mm has long been the standard, many units are moving back to the long-proven fight-ending punch of the .45 ACP. Keeping multiple rounds on target out of a submachine gun has proven a challenge. With the unique recoil system of the Vector, it's much easier to put multiple rounds on your target.
  • It uses standard Glock 21 magazines. Available in standard 13-round capacity, the magazines fit flush into the bottom of the mag well. However, since it's an SMG, KRISS-TDI has contracted a well-known company to manufacture 17-round extensions that are easy to put on the 13-round Glock magazines. The end result, if you do the math, is a 30-round magazine for your subgun.

     How fast you burn through those rounds is a different matter. The Vector gives you several choices. A selector lever lets you go from safe to semi to two-round burst to full auto. Why two-round? This was some feedback we received from professionals. Most agencies today train to engage lethal threats with a controlled-pair — formerly referred to as a double-tap, or two rounds fired quickly at the target.

     Given the typical muzzle-climb with an .45 ACP subgun, if it was a three-round burst, we'd have a hard time keeping the third round on the target. At a distance of about 7 yards, the spread on a two-round burst is only between 4 and 6 inches. However, at 15 yards that opens up to about 10 or 12 inches. If your initial point of aim is the low abdomen, your second hit will be in the chest.

     When you look at the overall Vector design you find that it was well thought-out in that it is designed to work with today's most common accessories. Above the barrel, in the receiver housing, is an integral flashlight mount with holes allowing for direction of a remote pressure switch on either side. This is imperative, as the weapon is designed to be 100 percent ambidextrous anyway.

     The top of the receiver has a length of Picatinny rail for mounting optics, and there's a shorter rail under the barrel to mount a vertical handle if you want one. Without such a handle, the front of the magazine well — which flows into the housing for the recoil block — serves as a front grip area. In lieu of optics for the top rail, the Vector has detachable sights that collapse out of the way if you are using optics, or easily pop up if you need them.

     The Vector's cyclic rate of fire is much higher than what I've dealt with in the past, being in excess of 800 rounds per minute. The early prototypes I fired had a cyclic rate of about 1,100 rpm, but they've slowed that down some. From what the engineers tell me, they can reduce that down as low as 600 to 700 rpm if an agency really requires it. But to date, no one has expressed displeasure with the 800 rpm they're using now.

     KRISS-TDI is working with several suppressor manufacturers to come up with a sound suppressor that works efficiently with their system. Obviously, several suppressors currently on the market would work here. But they want something that will work at maximum efficiency with their system, not something that works "just fine."

     For those of you who don't want a subgun, but really like the idea of the recoil system, KRISS-TDI is now marketing the Vector CRB/SO semi-auto-only variant with a 16-inch barrel and fixed stock.

     So if the idea of being able to put accurate .45 ACP rounds on a target 100 yards away sounds like something you might (unfortunately) have to do, you should check out this weapon. Reduced felt recoil combined with increased accuracy is never a bad thing in the world of firearms.

     Frank Borelli is the editor-in-chief of, the official Web site of the Cygnus Law Enforcement Group.

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