9×21mm Gyurza

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.

9x21 RG054 cartridge - the predecessor of SP10.
Place of originRussia
Service history
Used byFSB
Russian Army
Production history
Produced1990s to the present
VariantsSP-10 (7N29), SP-11 (7N28), SP-12, SP-13 (7BTZ)
Case typeStraight walled, rimless
Bullet diameter9.05 mm (0.356 in)
Shoulder diameter9.6 mm (0.38 in)
Base diameter9.9 mm (0.39 in)
Rim diameter9.9 mm (0.39 in)
Rim thickness1.2 mm (0.047 in)
Case length20.9 mm (0.82 in)
Overall length32.7 mm (1.29 in)
Ballistic performance
Bullet mass/type Velocity Energy
6.7 g (103 gr) 7N29 410 m/s (1,300 ft/s) 563 J (415 ft⋅lbf)
7.9 g (122 gr) 7N28 390 m/s (1,300 ft/s) 601 J (443 ft⋅lbf)
7.2 g (111 gr) 7BTZ 395 m/s (1,300 ft/s) 562 J (415 ft⋅lbf)
Source(s): Modern Firearms


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 6.7 g (103 gr) bullet at 410 m/s (1,300 ft/s) with 560 J (410 ft⋅lb) of muzzle energy, and will reportedly penetrate two 1.2 mm titanium plates, plus 30 layers of Kevlar, at 50 m (160 ft). 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.[1]


SP-10 (7N29) - armor-piercing bullet with hardened steel core[2]

SP-11 (7N28) - standard FMJ bullet with lead core

SP-12 - low ricocheting, expanding bullet[3]

SP-13 (7BT3) - tracer AP bullet based on 7N29


  • 9×21mm Gyurza
  • 9mm Gyurza


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