Glock 21 GEN 3 for sale
(15)
Glock 21SF Gen 3 .45 ACP Pistol, Black - PF2150201
Brand:
Glock
Action:
Double Action
Barrel Length:
4.61
Caliber:
.45 ACP
Capacity:
10+1
Finish Per Color:
Black
Marketplace Insights
★ 4.7/5
based on 15 customer reviews across 1 variants from 21 retailers
Customers overwhelmingly praise the Glock 21 for its reliability, accuracy, and ergonomic design, though some report retailer issues with magazine specifications.
What customers like
Reliability & Performance67%
My pistol has never jammed. It is a performer!
Accuracy & Shooting47%
I was shooting 2" groups at 5 yards. very accurate
Ergonomics & Comfort40%
Nice feel in the hand, shoots nice, easy to handle.
High Capacity Magazine27%
13+1 in .45 caliber is no joke.
Ease of Maintenance20%
Cleaning is a breeze.
Common concerns
Magazine Specification Issues13%
I was certain that I ordered the model with 13 round magazines and received 10 round mags
Retailer Service Problem13%
Not happy with Bass Pro on this sale, they get 1 star.
Frequently Asked Questions
Glock 21 GEN 3 for sale
Is the Glock 21 Gen 3 reliable?
The Glock 21 Gen 3 is widely considered reliable, functioning consistently with standard .45 ACP ammunition across thousands of rounds. Its striker-fired design has a strong track record in law enforcement and civilian use. Regular cleaning and factory ammunition maintain optimal performance.
When was the Glock 21 Gen 3 made?
Glock Gen 3 production began in 1995 and included the full-size Glock 21. Gen 3 remained in production until Gen 4 launched in 2010. Individual pistols carry serial numbers that can be used to determine their specific manufacture date.
Will a gen 3 Glock 21 slide fit a gen 4?
Yes, a Gen 3 Glock 21 slide fits a Gen 4 frame and functions correctly. The recoil spring assemblies differ between generations, so use the appropriate one. A small cosmetic gap may appear at the front of the frame but does not affect reliability.
What gen is the best Glock 21?
"Best" depends on your priorities. Gen 3 offers proven reliability and is widely available used at lower prices. Gen 4 adds adjustable backstraps for better ergonomics. Gen 5 includes front serrations and MOS optics compatibility. Most shooters consider Gen 4 or Gen 5 the best overall value.
What's the difference between a gen 3 and gen 4 Glock 21?
Gen 4 adds interchangeable backstraps, an enlarged reversible magazine release, and rougher grip texture. It also uses a dual recoil spring assembly, while Gen 3 uses a single recoil spring. Both chamber .45 ACP. The differences include ergonomics and internal components.
Will Glock 21 Gen 4 Mags fit Gen 3?
Yes, Gen 4 mags fit Gen 3 Glock 21s without issue. The only difference is the cutout for the ambidextrous mag release on Gen 4. Since Gen 3 uses a single-sided release, Gen 4 magazines function normally in the older gun.
Can you put a threaded barrel on a Glock 21?
Yes. Threaded barrels for the Glock 21 are available as drop-in replacements, typically threaded .578x28 TPI for .45 ACP suppressors. They fit Gen 3 and Gen 4 models. Threaded barrels are restricted or prohibited in several states, including California, New York, and Connecticut.
What frame does a Glock 21 have?
The Glock 21 has a full-size polymer frame. The 21SF variant features a slimmer, reduced-circumference frame. Gen 4 and Gen 5 models add interchangeable backstraps for grip customization. All versions are striker-fired and chambered in .45 ACP.