# Glock 21 Gen5 MOS .45 ACP Pistol - Precision, Power, Versatility **Brand:** Glock **Category:** Full Size Handguns **Caliber:** .45 ACP ## Specifications - **Caliber:** .45 ACP - **Barrel Length:** 4.61" - **Capacity:** 13 rounds - **Finish:** Blued - **Weight:** 29.81 oz - **Overall Length:** 6.5" - **UPC:** 764503054419 - **SKU:** UCDSUKuA7 ## Description The Glock 21 Gen5 MOS is a striker-fired semi-automatic pistol chambered in .45 ACP. The 4.61-inch barrel sits in an 8.03-inch overall package that weighs 1.81 lbs (27.68 oz) unloaded. Capacity is 13 rounds. The white dot front and white outline rear fixed sights are standard; the MOS slide accepts compatible red dot optics directly. The polymer frame includes interchangeable backstraps and ambidextrous controls. ### Key Specifications - **Model**: Glock 21 Gen5 MOS - **Caliber**: .45 ACP - **Action Type**: Striker-fired semi-automatic - **Barrel Length**: 4.61 inches - **Capacity**: 13 rounds - **Weight**: 1.81 lbs (27.68 oz) - **Finish**: Black polymer frame with matte black slide - **Sights**: Fixed white dot front sight & white outline rear sight ### Detailed Features 1. **Polymer Frame**: Durable and light, absorbs some recoil and keeps total weight down for a full-size .45 ACP platform. 2. **Glock Marksman Barrel (GMB)**: Precision-cut rifled barrel for consistent accuracy. 3. **Safe Action System**: Three passive safety mechanisms (trigger, firing pin, and drop safety) operate automatically without a manual safety lever. 4. **Ambidextrous Design**: Reversible magazine catch and ambidextrous slide stop levers for left- and right-handed use. ## Frequently Asked Questions **Q: What caliber is the G21?** A: The G21 is chambered in .45 ACP. **Q: Who makes the G21?** A: The G21 is made by Glock. **Q: What type of firearm is the G21?** A: It is a full-size, striker-fired semi-automatic pistol. **Q: What is the barrel length of the G21?** A: The G21 has a 4.61-inch barrel. **Q: How many rounds does the G21 hold?** A: The G21 has a 13-round capacity. **Q: Is the G21 optic-ready?** A: Yes. The MOS slide is cut to accept compatible red dot sights using adapter plates. **Q: Where can I buy the G21?** A: Compare current vendor offers on this page. ## What Reviewers Say *Quoted verbatim from YouTube reviews. Each link opens the video at the moment quoted.* > A lot of people feel like that this silhouette just hasn't changed and really it hasn't that much but the big difference is in the internals. > > — [sootch00](https://www.youtube.com/watch?v=NG2kojKqp7A&t=203s) > Big thing is the finger grooves you know the removal of the finger grooves to me really makes a huge difference with this pistol because the grip is already large. > > — [sootch00](https://www.youtube.com/watch?v=NG2kojKqp7A&t=295s) > Glock is known for having a little bit of a mushy trigger. > > — [sootch00](https://www.youtube.com/watch?v=NG2kojKqp7A&t=883s) > Your brake it's not all that great it's not very crisp but it's much better than the earlier gen models. > > — [sootch00](https://www.youtube.com/watch?v=NG2kojKqp7A&t=906s) > This is a man's gun if you got the moxie. > > — [sootch00](https://www.youtube.com/watch?v=NG2kojKqp7A&t=1073s) ## What Customers Say *AI-generated insights from customer reviews* The Glock 21 Gen5 MOS draws predictable feedback. Owners who buy a full-size .45 ACP Glock generally know what they're getting, and the Gen5 iteration earns broadly positive marks. Accuracy is consistently called out as a strong point. The Glock Marksman Barrel improved on earlier Gen3/4 barrel designs, and owners report tight groupings at typical defensive and range distances. Reliability holds up across reports, with minimal malfunctions under regular use. The .45 ACP caliber generates its own sub-discussions. Supporters cite stopping power as the primary argument; others point to 9mm's higher capacity and lower recoil for the same or smaller frame size. Neither position dominates in community threads. The MOS optics system is appreciated by those who want a red dot, though some users mention that zeroing can take extra effort. Ergonomics are good for most hand sizes but the full-size .45 frame works against concealed carry, which is a common observation rather than a complaint. Weight and size are intentional trade-offs for the home defense and range shooting use cases where this pistol fits best. Aftermarket support for the G21 is deep across holsters, sights, and accessories. ## Pricing **1 offers available** | Vendor | Price | |--------|-------| | Gunbuyer Com | $649.99 | ## Similar Products - [Glock 20 Gen5 MOS 10mm Pistol - 15rd, Lightweight Matte Black](https://gunsnation.com/p/glock-20-gen5-mos-10mm-pistol-15rd-lightweight-matte-black/UCDSUKu7l) - [Glock G21 Gen5 MOS .45 ACP 13rd Optics-Ready Pistol - Black](https://gunsnation.com/p/glock-g21-gen5-mos-45-acp-13rd-optics-ready-pistol-black/UCDSUKvYr) - [Glock 21 Gen5 MOS .45 ACP Pistol with Modular Optics, Black](https://gunsnation.com/p/glock-21-gen5-mos-45-acp-pistol-with-modular-optics-black/UCDSUKw2Z) - [Glock 43X MOS Gen1 9mm Compact Optic-Ready Pistol - Black](https://gunsnation.com/p/glock-43x-mos-gen1-9mm-compact-optic-ready-pistol-black/UCDSUKtME) - [Glock G21 Gen 5 MOS .45 ACP Gray Optics-Ready Pistol - 13rd Capacity](https://gunsnation.com/p/glock-g21-gen-5-mos-45-acp-gray-optics-ready-pistol-13rd-capacity/UCDSUKw15) - [GLOCK G21 Gen 5 MOS .45 ACP Optics-Ready Semi-Auto Pistol](https://gunsnation.com/p/glock-g21-gen-5-mos-45-acp-optics-ready-semi-auto-pistol/UCDSUKvy0) --- *Data from [GunsNation](https://gunsnation.com)*