SIG Sauer Mosquito

SIG Sauer · Pistol · Discontinued · 2005

Also known as: MOS-22-B, SIG Mosquito

Overview

The SIG Sauer Mosquito is a semi-automatic pistol chambered in .22 Long Rifle, produced by SIG Sauer since 2005.

Specifications

Weight (empty)698 g (24.6 oz)
Weight (loaded)760 g (26.8 oz)
Overall Length183 mm (7.20")
Barrel Length99 mm (3.90")
Height135 mm (5.31")
Width38 mm (1.50")
Sight Radius140 mm (5.51")
Action TypeBlowback
Firing MechanismDouble Action Single Action
Trigger TypeDouble Action
Trigger Pull20 N (4.5 lbf)
Magazine Capacity10 rounds
Magazine TypeDetachable Box
Muzzle Velocity330 m/s (1083 fps)
Muzzle Energy141 J (104 ft·lbf)
Effective Range25 m (27 yd)
Maximum Range150 m (164 yd)
Barrel RiflingRight Hand
Rifling Twist406 mm (15.98")
Number of Grooves6
Frame MaterialPolymer
Slide MaterialAluminum
Barrel MaterialSteel
FinishBlued

Calibers

Features

Variants

Service history

Operators

Production

Production years: 2005-2013

Manufactured by German Sport Guns (GSG) under SIG Sauer branding; exact production numbers not disclosed

Origin

Country of origin: Germany

Discontinued: 2013

Notes

The Mosquito was the first SIG Sauer-branded pistol with the barrel permanently formed into the frame. Manufacturing was contracted to German Sport Guns GmbH (GSG), and after SIG discontinued the Mosquito, GSG continued selling their own version as the GSG FireFly through American Tactical Imports. The pistol was notably finicky about ammunition, performing best with high-velocity .22 LR loads (CCI Mini-Mag being the most commonly recommended). Low-velocity or bulk ammunition frequently caused cycling failures. Despite SIG's branding, the Mosquito was widely considered the least reliable product in the SIG Sauer lineup.

Background

The Mosquito is often considered the black sheep of the SIG Sauer family. Despite bearing the prestigious SIG name, it was entirely designed and manufactured by German Sport Guns, a company known for affordable rimfire replicas. Its chronic reliability issues led many shooters to joke that the Mosquito was 'the SIG that SIG didn't make.' After discontinuation, GSG continued production under their own brand as the FireFly.