GLOCK G21 Short Frame .45 Caliber Auto Pistol


Remarkable for its accuracy and light recoil, the GLOCK 21SF delivers the legendary stopping power of the .45 AUTO round with 10/13 round magazine capacity. Countless law enforcement units swear by the G21SF pistol, and that's why this powerful, lightweight, all climate workhorse is standard issue from the North to South Poles. The SF model reduces the circumference of the receiver at the rear, or "back strap," offering increased comfort and control—especially for shooters with smaller hands.

Polymer Frame
The GLOCK, non-fiberglass, reinforced polymer frame helped revolutionize the handgun industry by delivering a new standard in high-impact resistance, durability, and extended life—all while reducing weight by a full 90%. Stronger than most metals, polymer is temperature neutral, requires less maintenance, and most users report substantially less felt recoil than with metal frames.

“Safe Action”® System
The GLOCK “Safe Action”® System is made up of 3 independent, automatic safeties designed to ensure the pistol cannot fire unintentionally due to inertia or any impact. The trigger must be moved completely to the rear to deactivate these safeties. Once released, all 3 safety features reengage and the pistol is automatically secured again.

Barrel Design
GLOCK barrels are manufactured using a cold-hammer forging method, with surface treatment and rounded interior profiles allowing for uniform precision and consistency—even after a high number of rounds have been fired. Plus, polygonal rifling leads to a better gas seal that translates to higher velocities, increased accuracy, and a substantial reduction in maintenance.

Nitrite Treatment
All GLOCK metal parts are treated with a Nitration finishing process that optimizes the molecular structure of those surfaces. This progressive technology delivers a high degree of surface hardness, maximum durability, and exceptional corrosion resistance, that provides many years of trouble-free service under the harshest environmental conditions.

Often overlooked, the magazine is one of the most critical components of a pistol. The GLOCK precision-made, stagger-column, high-capacity device is designed to reliably feed all ammunition types. Lightweight and strong, with a polymer shell enclosing a metal liner, this easy to disassemble magazine insert is engineered to be a strong and secure unit for years of outstanding performance.

Caliber / System
.45 AUTO / Safe Action

Length: 204 mm / 8.03 in.
Width: 32.50 mm / 1.27 in
Length between sights: 172 mm / 6.77 in
Height: 139 mm / 5.47 in.
Barrel height: 32 mm / 1.26 in.
Barrel length: 117 mm / 4.60 in.

Unloaded: 830 g / 29.30 oz.
Loaded: 1085 g / 38.30 oz.

Trigger Pull/Travel
Trigger pull: ~2.5 kg / ~5.5 lbs.
Trigger travel: ~12.5 mm / ~0.49 in.

Barrel Rifling/Length of Twist
Barrel rifling: right hand, octagonal
Length of twist: 400 mm / 15.75 in.

Magazine Capacity
Standard: 13
Optional: 10

GLOCK G21 Short Frame .45 Caliber Auto Pistol
Fixed, Adjustable or GLOCK Night Sight

Preventative Maintenance Instructions

Can I dry fire my Glock pistol?
It is ok to dry fire your Glock pistol, but in situations where the pistol will be subjected to continuous sessions of dry firing, the use of a snap cap or dummy round is recommended.

What kind of ammunition should I use in my Glock pistol?
Do not use reloaded, remanufactured, or handloaded ammunition because it may not meet applicable SAAMI, CIP or NATO standards and could cause death, serious personal injury, or property damage. Only use high quality commercially manufactured ammunition in the same caliber as your Glock pistol. (Note: Use of reloaded, remanufactured, or handloaded ammunition will void the warranty).

Can I use +P and +P+ ammunition?
Glock suggests using ammunition that is manufactured and meets SAAMI or industry specifications. If you are not sure the ammunition brand or type you choose is safe for use, call the ammunition manufacturer and ask if the product meets SAAMI guidelines before using it in you firearm. Some +P ammunition meets these guidelines, +P+ normally does not. This ammunition may generate a higher pressure over the standard loadings, and may shorten the component life of your firearm.

Can I use lead bullets?
No, we recommend the use of jacketed ammunition only.

Can I find out my Glock pistol’s born on date?
Yes, you can find out the manufacture date of your Glock pistol by contacting Glock, Inc.

Can I purchase a frame or slide from Glock Inc?
No, Glock Inc does not sell frames or slides.

Can I convert my .40 Cal. pistol to .357 Sig or .357 Sig to .40 Cal.?
Yes, in most cases, by the substitution of the barrel you can convert the Glock pistol to another caliber. However, early models may not qualify for a conversion. Contact Technical Services if unsure.

When I disassemble my pistol, I notice that the recoil spring is no longer seated on the assembly notch of the barrel. Is this normal?
Yes, the assembly notch is for assembly only. The recoil spring assembly drops down into the frame recess where it stays until disassembly when the slide and barrel come forward picking it up out of the lower position, hence the appearance of dropping out of position.

Have Questions? Call +1 (855) 729-0446 to speak with a specialist.