Glock 21 MOS Gen 5 Initial Impressions ~ VIDEO

U.S.A. -( While rumors of the Glock 47 existed for some time before SHOT Show 2023, news of the Glock 21 Gen 5 MOS wasn’t nearly as well known.  And this is unfortunate, as many shooters – including myself – have been patiently awaiting the release of a Gen 5 MOS Glock 21/20 to use as a hunting companion, home defense tool, or suppressor host. Now that SHOT Show 2023 is beginning to wind down and I’ve had a chance to put a few rounds through both big bore blasters I can finally say that it was worth the wait.

Glock 21 Gen5 MOS 45 ACP
The .45 ACP Glock 21 Gen 5 MOS as seen on the SHOT Show 2023 floor. IMG Jim Grant

Glock 21 MOS Gen 5

Chambered in the classic 45 ACP cartridge, the latest edition of the Glock 21 still holds the same 13 rounds in a flush-fitting magazine as before and delivers these rounds with the same die-hard reliability as always. That said, there are a few new features that the Gen 5 MOS brings to that table that will interest shooters.

For starters, the Gen 5 models no longer feature finger grooves on the grip frame which makes the gun fit a larger variety of shooters since their hands won’t have to perfectly conform to said grooves.

On the other side of the gun, the frame now features forward serrations for ease in clearing malfunctions or performing a chamber check to ensure a gun is loaded or unloaded. But as an MOS model, the biggest change is the addition of an RMR footprint mount at the rear of the slide, allowing shooters to mount their favorite optic to the new Glock without any special adaptors.

There are other changes that we’ll go over in the future, when one of these fine firearms finds its way to the Ammoland T&E Lab where we’ll put it to the test.

About Jim Grant

Jim is one of the elite editors for, who in addition to his mastery of prose, can wield a camera with expert finesse. He loves anything and everything guns but holds firearms from the Cold War in a special place in his heart.

When he’s not reviewing guns or shooting for fun and competition, Jim can be found hiking and hunting with his wife Kimberly, and their dog Peanut in the South Carolina low country.

Jim Grant

Notify of
Most Voted
Newest Oldest
Inline Feedbacks
View all comments

Serrations on the frame? Perhaps ya need a new proof reader……………


I wish Glock would make their slides about 50-50 with and without the forward serrations. Some of us think they look absolutely stupid.

Texas Patriot

Grigori…. It’s all about function. If it’s hot & humid outside (or inside) it’s all about the grip and safety. When the good Lord set about things, not all of us were blessed with hands sufficiently abundant, with adequate size to handle feed, misfeed or the grip required to clear certain feed and/or extraction issues inherent to the Glock 20 or 21. The grip serrations may well assist many of us in safely dealing with such matters. Safety and handling were paramount when in Vietnam, Central America, and later in the Persian Gulf.


So have serrations cut into the original slide as I did.


Other calibers too?