The KRISS Vector has undergone two generations of modification. The
Gen I version is the baseline model of the Vector family. It was later replaced by the improved
Gen II version which features a redesigned pistol grip and trigger and has the swing angle of the
safety lever reduced from 120 to 45 degrees. The Gen II also eliminates the opening above the barrel for the original Vector's optional
Surefire weapon light, since these are no longer manufactured. In addition to the original Flat Black finish, optional factory Cerakote coatings now come in Olive Drab (green), Flat Dark Earth (tan), Alpine (white), or Combat Gray. The
Vector SMG variant is only available for military and law enforcement use. It features a 5.5-inch barrel (with an option of a 6.5-inch barrel on the Gen II version), a folding stock, flip-up Midwest Industries back-up iron sights (BUIS) (KRISS Sights on Gen II weapons), a full-length Picatinny rail for mounting various optics/scopes, and either two mode fire selector (single and full-auto) or a three mode fire selector (single, two-round burst and full-auto). The Vector SMG is only available in .45 ACP and 9×19mm Parabellum; Due to the nature of its design, the auto trigger pack is not compatible with any semi-automatic Vector lower. The 9mm model uses
Glock 17-compatible magazines (typically the extended 33-rounder used by the Glock 18) and the .45-caliber model uses Glock 21 magazines. Semi-automatic variants are produced and available for the US civilian market. There are three main configurations, the Vector CRB, Vector SBR and Vector SDP. In addition to
9×19mm Parabellum and
.45 ACP, they can also be chambered in
.40 S&W (using Glock 22 magazines),
10mm Auto (using Glock 20 magazines), or
.357 SIG (using Glock 31 magazines). A variant chambered for
9×21mm IMI that feeds from standard 9×19mm Glock 17 magazines is available for the Italian civilian market. The
.22 LR variant feeds from a proprietary 10-round magazine, and functions using a traditional straight blowback operating system rather than the Super V delayed system. The Canadian (and some American) civil market versions only come with the blocked 10-round magazines rather than the full capacity magazines. Like the Law Enforcement / Military SMG models, the civilian model Vectors can be converted to chamber and fire other calibers if the lower receiver groups are changed. • The
Vector CRB (carbine) is a semi-automatic carbine with a permanently affixed barrel shroud to the standard 5.5-inch barrel, extending it to , intended for states with short-barrel rifle bans, with an 18.6-inch (470 mm) version produced for the Canadian market. The standard model has a folding stock (fixed in states where state law prohibits). Variants exist for compliance with various state gun laws, including a California-legal "featureless" variant with a Kydex grip-wrap barrier (prohibits gripping the back of the pistol grip), a hand stop replacing the usual vertical foregrip, and a permanently affixed Defiance DS150 stock to give an overall length of 36.5-inch (930 mm). • The
Vector SBR (
Short Barrel Rifle) is a semi-automatic short-barreled configuration featuring the same 5.5-inch barrel as the selective fire submachine gun. • The
Vector SDP (
Special Duty Pistol) is a semi-automatic pistol configuration that has a permanently affixed cap with a sling mount in place of a folding stock. There is also a configuration of the Vector SDP fitted with an SB Tactical arm brace called the
Vector SDP-SB (
Special Duty Pistol – Stabilizing Brace). The "Enhanced" versions of the Gen II CRB and SBR are also available with collapsing M4-style stock adaptors instead of the standard folding stock (with a
Magpul UBR stock included) and a rectangular
barrel shroud for the CRB, though these accessories can also be purchased separately. ==Derivatives==