The 9×21mm Gyurza (Гюрза, Russian for "blunt-nosed viper") round is a Russian handgun round designed to defeat body armor that was developed by TsNIITochMash for its SR-1 Vektor semi-automatic pistol and SR-2 Veresk submachine gun.
Performance The method of construction of the rounds allows them to be effective against both unarmored and armored targets. The bullet has a hard sub-caliber core contained within an outer sleeve and separated from it by a polyethylene layer. If the bullet strikes an unarmored target, it holds together to produce a wide wound channel. If the bullet strikes an armored target, the sleeve is stripped away, and the core penetrates alone. The 7N29 AP loading fires a bullet at with of muzzle energy and will reportedly penetrate two 1.2 mm titanium plates, plus 30 layers of Kevlar, at . The disadvantage of the rounds is that high impact velocities are needed for them to work effectively, so the bullets are relatively light to maximize their muzzle velocity. This means they will lose velocity relatively quickly, limiting their effective range.
Variants SP-10-UCH – unloaded training cartridge
SP-10 (7N29, sometimes referred to as RG052 or RG054) – armor-piercing bullet with hardened steel core
SP-11 (7N28) – standard FMJ bullet with lead core
SP-12 – low ricocheting, expanding bullet
SP-13 (7BT3) – tracer AP bullet based on 7N29
SP-17 – bullet with reduced environment penetration
Designations 9×21mm Gyurza 9mm Gyurza
Platforms SR-1 Vektor SR-2 Udav SR-2 Veresk Gepard (submachine gun)
See also 9x19mm 7H21, 9x19mm 7H31 — Armor-piercing variant of 9×19mm Parabellum 9×30mm Grom — Uses RG054 bullet 9x21mm - 9x21mm pistol cartridge distinct from 9x21mm Gyurza, as a result of different cartridge dimension measuring systems. Sometimes referred to as 9x21mm IMI, GP, or Winchester
Notes
External links 9×21mm pistol cartridges 9x21mm Ammunition (Russian) SR-1 Vector - Modern Firearms SP Ammunition - Modern Firearms