The Glock 19 is Glock’s “Compact” pistol. It’s got a barrel length of just over four inches, has a height of about five inches, depending on sights, and holds 15 rounds in a magazine. It’s a great compromise between concealability and fightability, since it’s about as small as a pistol can be and still allow the vast majority of adults to get a full grip on the gun. The Glock 19 is a strong seller in the US civilian market, but it is also popular in SOCOM. They’ve even type-classed the Glock 19 Gen4 MOS. And the USMC has just ordered a large number of Glock 19Ms. And all this despite SIG winning the US Army’s Modular Handgun contract.
SOCOM has been the big user of Glock 19s for years in the DoD, so let’s look at them first. They’ve type-classed the Glock 19 Gen4 MOS with threaded barrel as the Mark 27. Type classing assigns a national stock number and makes it easy to order more in the future. SOCOM is a big user of the Glock 19, and this shows an eye towards the future of pistol sights: micro red dot optics. SOCOM’s current pistol red dot of choice is the Leupold Deltapoint Pro. While they could have selected a custom-milled solution, choosing the MOS model gives them something that can be ordered direct from the factory, and it allows them to easily switch optics in the future if desired.
The choice of Deltapoint Pro may be noteworthy, if only because it’s not the RMR that’s so commonly seen for duty-type applications. The RMR has significantly better battery life, and may be a bit tougher than the Deltapoint Pro. The Deltapoint Pro’s larger window makes it a bit easier for shooters to get used to, since there’s a larger area where they can see the dot. The biggest advantage of the Deltapoint Pro is that one can replace the battery without having to remove (and rezero) the optic. This more than makes up for the less than ideal battery life. Batteries can be easily swapped before missions or training sessions, without having to then verify the zero of the optic.
The Marines have opted for the same Glock 19M that the FBI adopted. Of course, the FBI also adopted the Glock 17M, and the reader may be wondering why not that pistol? Let’s consider the intended users. The Marines may espouse the concept of ‘Every Man a Rifleman’ but there are some jobs where this just doesn’t work. Pilots for example. A pistol also gives the option of carrying concealed, which is great for criminal investigators, and those conducting interviews. Or those that need to be around questionable allies. It allows the soldier to be armed without appearing to be armed. So the Marines are coming at it from the same way so many concealed carriers are: the Glock 19 is just about the perfect size. Smallness helps concealment, especially with respect to the “height” or “length” of the grip. And the Glock 19’s grip is about as small as it can be and still allow the user to get a full grip on it (i.e. no fingers are hanging off to be curled below it). The Glock 19 doesn’t give up much to the Glock 17 as far as shootability goes, but it’s quite a bit more concealable. For those who aren’t needing concealment, the pistol is still a secondary weapon system. A smaller, lighter pistol is easier to fit on their gear in a cockpit with all the other stuff they have to carry. Or on their belt for SOCOM.
The reader may also be wondering “Why not the P320 Compact?” Well, the Marines do have a history of working a lot with both SOCOM and the FBI, and they both like Glocks. Also, the MHS program was not as thorough as the FBI’s tests were as far as high round count reliability tests are concerned. The full-size MHS entrants (P320) went through 12,500 rounds to check reliability and establish an MRBS of 2,000 rounds with a 90% confidence level. The compact entrants (P320C) only had to go through 1,500 rounds of evaluation. The FBI tests included 20,000 rounds for each of the full size and compact entrants. So the Glock 19M has verified reliability in a way that the P320C doesn’t.