When a police agency retires a duty pistol, it often ends up as a trade-in like this Glock 21 Gen4. It is a full-size, striker-fired handgun chambered in .45 ACP, with a 4.61 inch barrel and a 13 round double-stack magazine. One magazine is included.

The seller points out that law enforcement trade-ins are usually fired less than other used guns, since most officers only shoot to qualify. They carry cosmetic wear from daily duty, such as holster marks, but the barrel and internals are often in good shape. Those are general remarks about trade-ins, not a grade for this specific pistol, so look closely at the photos.

The G21 is a big pistol with a wide grip, so it fits larger hands best. Gen4 added a reversible magazine release and a dual recoil spring that tames the .45's push. It is used and sold as described. Check the slide, the finish and the sights when it arrives. With only one magazine in the box, consider buying a spare or two.

A trade-in G21 is a straightforward, hard-working .45 at a modest price. It ships to a licensed dealer you choose, where you finish the background check and pick it up.