Glock G21 Gen5 MOS .45 ACP – Full-Size, Optics-Ready, KKM Precision Threaded Barrel
This Gen5 Glock 21 brings the proven .45 ACP platform forward with Glock’s latest updates and a high-grade KKM Precision 5.25-inch threaded barrel already installed. It is the first factory MOS-cut G21 to combine ambidextrous controls, the Gen5 Safe-Action upgrades, and extended optics capability in a single full-size package—making it a notable option for shooters who want modern features in a hard-hitting caliber.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling – Sharp lands and grooves.
What’s Included
- Factory Glock G21 Gen5 OEM barrel (non-threaded)
- KKM Precision 5.25 in threaded barrel with knurled thread protector (installed)
- Three 13-round Glock .45 ACP magazines with orange followers
- Two Glock Gen5 beavertail backstraps
- Glock factory hard case with matching serial label
Gen5 engineering gives this G21 ambidextrous slide-stop levers, a reversible magazine catch, and Glock’s updated Safe-Action fire-control components. Together, these enhancements make manipulation straightforward for both right- and left-handed shooters.
The factory MOS cut accepts today’s popular micro red-dot footprints, while front and rear cocking serrations add traction for press checks and slide manipulation. The nDLC matte-black finish on the U.S.-made slide and frame resists corrosion and wear.
KKM’s 416R stainless-steel barrel extends to 5.25 inches, uses conventional rifling, and is threaded 1/2-28 TPI for quick suppressor or compensator installation. The longer sight radius and match-grade bore provide a tangible accuracy boost over the standard barrel.
Three 13-round magazines with high-visibility orange followers match the late-Gen5 .45 design, supporting reliable feeding and positive round-count checks. Two interchangeable beavertail backstraps allow the grip to be tailored to individual hand size.