Glock G21 SF
Glock Ges.m.b.H. · Pistol · In Production · 2007
Also known as: G21 SF, G21SF, Glock 21 Short Frame
Overview
The Glock G21 SF is a semi-automatic pistol chambered in .45 ACP, produced by Glock Ges.m.b.H.
Specifications
| Weight (empty) | 740 g (26.1 oz) |
| Weight (loaded) | 1100 g (38.8 oz) |
| Overall Length | 205 mm (8.07") |
| Barrel Length | 117 mm (4.61") |
| Height | 140 mm (5.51") |
| Width | 34 mm (1.34") |
| Sight Radius | 172 mm (6.77") |
| Action Type | Short Recoil |
| Firing Mechanism | Striker Fired |
| Trigger Type | Safe Action |
| Trigger Pull | 28 N (6.3 lbf) |
| Magazine Capacity | 13 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 260 m/s (853 fps) |
| Muzzle Energy | 477 J (352 ft·lbf) |
| Effective Range | 50 m (55 yd) |
| Maximum Range | 1500 m (1640 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 400 mm (15.75") |
| Number of Grooves | 6 |
| Frame Material | Polymer |
| Slide Material | Steel |
| Barrel Material | Steel |
| Finish | Tenifer |
Calibers
- .45 ACP · primary — also known as .45 Auto, 11.43x23mm
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Trigger Safety, Firing Pin Safety, Drop Safety
- Features: Polymer Frame, Safe Action Trigger, Polygonal Rifling, Accessory Rail, Short Frame, Reduced Grip Circumference
Base model
Service history
Operators
- U.S. Special Operations Command
- Los Angeles Police Department (SWAT)
Production
Production years: 2007-present
SF variant of the G21 platform. Introduced to improve grip ergonomics on the large-frame .45 ACP model.
Origin
Country of origin: Austria
Designer: Gaston Glock
Notes
The G21 SF was introduced around 2007 as part of Glock's Short Frame initiative for the large-frame models. Weight without magazine is 740g (26.10 oz), slightly lighter than the Gen4 at 745g due to the absence of the modular backstrap hardware. The SF variant is built on Gen3 architecture -- it lacks the modular backstrap system, dual recoil spring, and RTF texture of the Gen4 and later models. The G21 SF was notably adopted by U.S. SOCOM as an interim sidearm option.
Background
The Glock 21 SF earned its most notable endorsement when U.S. Special Operations Command selected it as an option for operators who preferred the .45 ACP cartridge. SOCOM's adoption of the G21 SF was a significant validation for polymer-framed .45 pistols, demonstrating that even elite military units trusted the platform for the most demanding operational environments. The Short Frame modification made the big-bore Glock viable for operators who couldn't comfortably manage the standard frame's substantial girth.