Review: Kriss Vector Gen II SDP-SB 9mm G&A Staff November 20th, 2017 | More From G&A Staff Share0 Tweet Email The unusual shape of the Kriss Vector series and peculiar cycle of operation is far less remarkable now than it first was. Earlier models and generations have been in existence for nearly a decade, and its place in popular gun culture remains something less than ubiquitous. Still, its unique profile is recognizable, which is cause for several appearances in television shows, movies and video games. What is still remarkable to us about the Kriss Vector is the unconventional delayed blowback system. Kriss USA describes it as “Super V Recoil Mitigation.” The Vector’s in-line bolt mechanism redirects the recoil impulse down and into the angular forward grip instead of allowing the energy to travel rearward into the rear grip and stock as with a typical firearm. The typical design results in the muzzle rising, or flipping upward, as the mass of the bolt and carrier extend rearward before changing directions and returning to battery. The Kriss system, however, directs recoil energy back and down toward the shooter’s feet in an arc resembling a almost an L-shaped profile. It does so by pushing the articulated bolt assembly down into a cavity within the frame located behind the magazine instead of cycling rearward into a straight-line receiver extension. In turn, the effect is reduced felt recoil and a distinct shape. When firing, Guns & Ammo staff observed a little bit of a bounce, particularly when the bolt assembly cycled back up and forward into battery, but it was nothing that significantly impacted sight tracking or manipulations. G&A recently evaluated the SDP-SB in 9mm, which is the semiautomatic pistol configuration of the Vector Gen II. (SDP stands for Standard Duty Pistol.) It operates from the same closed-bolt, delayed-blowback system found in the semiauto Vector CRB rifles. Functionally, the SDP-SB model tested here is no different than standard SDP models, except that it includes a factory-installed SB Tactical Arm Brace at the rear of the receiver. This arm brace functions in lieu of the SDP’s quick-detach (QD) sling swivel point. The Vector Gen II SDP pistol is now available from Kriss with an SB Tactical arm brace intstalled. This gives the SDP-SB a short profile and makes it very controllable when shooting rapidly. The Vector trigger pull measured 51/2 pounds and could be described as Glock-like. However, our sample was a bit smoother and offered a clean break with minimal overtravel. Lower receivers are externally identical on all pistol models, which currently accommodate 9mm, .357 SIG, .40 S&W, 10mm and .45 ACP chamberings. The Vector allows endusers to quickly transition between calibers without tools. Shooters need to be aware that swapping lowers could affect the firearm’s classification (as of this writing). When changing between pistol configurations, it is not an issue. However, if one was to introduce a buttstock into the mix, the result would be a short-barreled rifle (SBR). SBRs are regulated by the National Firearms Act (NFA), and necessitate a tax stamp and the associated government paperwork. In this case, the Kriss SDP-SB is not classified as an SBR because it is a pistol with an SB Tactical Arm Brace installed. It can be purchased the same as any other semiauto pistol in your jurisdiction. In length, the SDP-SB stretches a little over 2 feet and features a 1/2×28 threaded barrel measuring 5½ inches and made of 4140 chrome moly steel. Inside is a 1:10-inch twist rate. The SDP-SB is made ready to fire by grasping a folding, non-reciprocating side-charging handle located immediately adjacent to the bolt release. Both are just above the forward face of the magazine well where it curves forward. The short-throw ambidextrous safety selector is then switched to fire with the flick of the firing-hand’s thumb. Ergonomically, the Vector Gen II series of rifles and pistols is a platform mixed with both superb and terrible qualities. To its designers’ credit, almost all controls are intuitive, easy to reach and simple to manipulate. Controls are easy to reach and intuitive to operate, while the gripping surfaces are generous and tactile. The compact design makes incredible use of minimal space to operate the delayed blowback system without compromising handling or controllability. The Vector II 9mm family (including the SDP-SB) is fed with Glock 17-type magazines. Therefore, capacity of the 9mm models is quite good at 17 or 33 rounds. Most of the aftermarket baseplates and magazine extensions designed for Glock magazines allow the capacity to be further increased. G&A tested function with several aftermarket magazine extensions, which included Arredondo, Taran Tactical and factory Glock “+” models. Each seated and locked firmly, while also dropping free. Kriss offers its own magazine extension called the MagEX, which was not available for the 9mm models at the time of this writing. The MagEX is available for .45-caliber Glock 21 mags, providing an increase in capacity from 13 to 25 rounds. The lower receiver contains the unique fire control group as well as the detachable magazine. The housing is given tactile serrations for positive grip. Speed reloading the SDP-SB was quick and easy. The angled slope of the front face of the magazine well and the proximity of the support hand helps in these matters. On the flip-side, we discovered that it was easy to unintentionally drop a magazine due to the location of the magazine release. This button was regularly and inadvertently contacted during the evaluation. G&A staff also found that when utilizing a high-support-hand, thumbs-forward, two-handed firing grip, we would unintentionally release the bolt when the action attempted to go to slide lock. Shooting with a flagged support side thumb extended vertically instead of toward the target mitigates the problem, but it’s difficult to readily establish this style of grip unless you habitually shoot that way. G&A’s SDP-SB sample suffered intermittent failure to extract malfunctions when initially test-fired. The resultant stovepipes were generated when using numerous factory magazines of known good quality and an assortment of factory ammunition. After approximately 150 rounds, the problems ceased. Once settled, the Vector II went on to chew through anything it was fed, including aluminum-cased Blazer 115-grain full metal jackets (FMJs) and a bucket of remarkably dirty handloads assembled for high-volume shooting. As such, G&A recommends a break-in period prior to relying on the platform to perform reliably. Formal accuracy testing produced surprisingly tight groups at 50 yards with Remington’s UMC LeadLess 147-grain load, producing a best five-shot group of 1.34 inches and an average of 1.53 inches. Bullet velocities were in the general range of identical rounds fired from 9mm semiautomatics with 4- to 5-inch barrels. Accuracy, however, was much improved. Kriss’ new SDP-SB delivered substantially tightened shot groups when compared to traditional striker-fired pistols. In its tested configuration, the Vector Gen II SDP is lacking potential in terms of practicality. Although technically a pistol, the SDP is too heavy for most people to operate single-handed, which is why the new SDP-SB model with stabilizing arm brace makes more practical sense. The SDP-SB is an excellent choice for those seeking to SBR the Vector Gen II using ATF Form 1 so that it can be enjoyed as a pistol while the SBR paperwork clears. If you’re patient, you might prefer one of the Vector Gen II SBR models, which features a newly designed side-folding stock that should be available later this year. Impractical does not necessarily equate to unappealing. With that said, G&A anticipates that those who pick up a Kriss Vector Gen II pistol won’t suffer much buyer’s remorse. The platform remains a hoot to shoot due to the lack of felt recoil and optional extended magazine capacity. It also serves as a great conversation piece, as it garnered significant attention each time it was brought to the public firing line. Share0 Tweet Email Load Comments ( ) Don’t forget to sign up! Get the Top Stories from Guns & Ammo Delivered to Your Inbox Every Week To sign-up for our newsletter, check this box and submit your email address below. 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