When you need a full-size, proven sidearm for home defense, duty use, or range work, reliability and ergonomics matter. This review focuses on a used but ready-to-run specimen that combines classic .45 AUTO performance with modern Gen4 handling enhancements.

GLOCK 21 G4 is a Gen4 full-size pistol chambered in .45 AUTO. The pistol features the Gen4 modular backstrap system and a rough textured frame (RTF) for improved grip ergonomics. This listing describes a used, good condition example with a matte black nDLC slide that shows light wear on edges consistent with normal holstering. Shop this product

Features and Ergonomics

The GLOCK 21 G4 retains the platform’s signature simplicity while adding Gen4 improvements. The modular backstrap system lets shooters tailor the grip to hand size, increasing control of the hard‑hitting .45 AUTO round. The rough textured frame provides a secure purchase in wet or stressful conditions. A 13‑round factory magazine gives ample capacity for a .45 ACP full‑size pistol.

Finish and Mechanical Condition

This pistol is described as used, in good condition. The nDLC slide finish has light edge wear, and the polymer frame is in good shape. Importantly, the bore is reported bright and clean with strong polygonal rifling, and the action is fully operational with reliable performance—details that matter when assessing a pre‑owned firearm.

Caliber, Capacity, and Practical Use

.45 AUTO remains a respected defensive cartridge for its proven stopping characteristics. In a full‑size platform like the G21 Gen4, the 13‑round standard magazine balances capacity with the cartridge’s ballistics, making this pistol suitable for duty, home defense, or range sessions. Note that legal limitations on magazine capacity vary by jurisdiction; buyers must verify local laws before purchase.

Included with the sale are the original Glock hard case, one (1) 13‑round factory magazine, the cleaning brush, and owner’s manuals/paperwork. The asking price is $550.99—an attractive entry point for a serviceable G21 Gen4 in good condition. View product details and pricing

Buying Notes

Confirm that possession of this model and the included magazine capacity is legal where you reside; compliance is the buyer’s responsibility. For current stock and secure checkout, check current availability on the product page where purchases are completed through the retailer. Check availability

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