GLOCK on a Stock

Mako Group’s KPOS PDW Conversion Kit Adds Stability and Accuracy 

KPOS PDW Conversion Kit Adds Stability and Accuracy

The KPOS Glock was lightweight and accurate with plenty of capacity thanks to the 33rd Glock magazines. The ability to mount the KPOS to the shoulder combined with ease of mounting optics and other devices as desired multiplied the Glock’s capability making the effort to SBR the package worthwhile.

In the United States, the KPOS converts your Glock pistol into a Short Barreled Rifle (SBR) classification and must be treated as such with an approved Form 1 from the BATF before installing a weapon in the KPOS. More importantly, once registered as an SBR, a weapon used with the KPOS is required to stay in this configuration and should not be used in other applications.

Serious shooters have long sought to double their pleasure by converting favorite hand-held weapons for additional duty at arm’s length. Examples date back to the era of black powder weapons, but the trend toward “stocking up” gained real momentum with the introduction of the Broomhandle Mauser (Mauser C96) around the turn of the previous century.

During the Cold War, owners of machine pistols such as the Beratta 93R, Stechkin, and HK VP70 took advantage of added stocks to benefit from the stability, controllability, and accuracy offered by firing from the shoulder. But as submachine guns and short-barreled rifles rose to the forefront around mid-century, conversion kits lost some hard-earned status.

Recently, however, the trend has enjoyed a revival of sorts, with interesting options appearing on the market to convert semi-automatic handguns into pistol caliber carbines by adding a rear stock.

Since many consider the Glock as a standard to which fighting pistols should be held, most stock conversion kits offer Glock-adaptable models, and the KPOS Glock PDW from the Mako Group is one of the best available. Designed with personal security details (PSD) and covert operations in mind—especially when the Glock 18 machine pistol is utilized—the KPOS makes this top-performing pistol even better.

The KPOS arrives with Picatinny style rails along the top, sides, and bottom. It comes in a hard case that includes a folding forward vertical grip, modified Glock slide back plate (for charging handle adaptation), and a detachable single point sling. The patented KPOS design locks both the front and back of the pistol into the KPOS frame without requiring any tools. The Glock’s railed dust cover is used as an attachment point in the front and a simple wedge block in the rear secures the frame. This prevents the pistol from moving, ensuring reliability and stable point of aim. The open sights are still accessible, though mounting a red dot or other type of optic is best for extending effective range.

The aluminum framed KPOS stock features a side-folding stock that further reduces weapon footprint when folded. The KPOS measure 13.5 inches with stock folded and 21.5 inches with stock deployed and weighs less than four pounds with a Glock 17 mounted.

For those who question the utility of employing a pistol cartridge in a shoulder-fired weapon, remember that most engagements happen within a 100-yard range, especially in a civilian setting, with handling and reliability playing more of a factor in quick, reactive engagements than specific caliber used. Less experienced shooters will find the lower recoil pulse and muzzle blast of a pistol caliber fired from the shoulder easier to manage, and this often translates to better accuracy.

Simply put, a Glock handgun is transformed into a more potent package when mated to the KPOS stock. For this review, I mounted a Glock 17 using a Lone Wolf Distributors stainless barrel with threaded muzzle in the KPOS. Although I did not utilize one for this test, the KPOS allows for the mounting of a suppressor, and the barrel shroud is easily removed allowing for a suppressor’s diameter.


When viewed from above, the Glock slide locked in the open position clearly does not interfere with positive function of mounted weapon with ejection port left clear. Picatinny-style mounting rails run the top of the KPOS allowing for sights to be mounted as user sees fit.

The primary advantage derived from the KPOS SBR is increased effective range and shootability, based on the KPOS’s multiple points of contact with the shooter. These primary points of contact are the shoulder and cheek, but an added benefit is the ability to spread your hands further apart for more stability. The KPOS’s rail system also maximizes potential with accessories such as optics, lights, lasers and a vertical forward grip, the latter of which aids greatly in weapon manipulation and stability when firing. For my test, I added a Sig Sauer STS 081 red dot sight to the KPOS’s top rail.

The Glock 17 used in conjunction with the KPOS conversion was a proven performer, with upwards of 4,000+ rounds fired without issue before being converted into a SBR via BATF Form 1 (see sidebar), and the Glock maintained its reliability once installed in the KPOS.

The Glock is secured into the KPOS unit

The Glock is secured into the KPOS unit via dust cover in the front and mounting plate in the rear that engages the handgun’s beavertail grip, keeping everything secure and ensuring that reliability and accuracy are maintained.

Down Range Testing

I tested a wide range of 9MM loads, including 115-grain, 124-grain, and 147-grain JHP and FMJ loads from Black Hills, CCI, Federal, Hornady, Remington, Winchester, and Wolf. The Glock KPOS SBR was sighted in one-inch high at 25 yards, which gives an approximate 50-yard zero and -7 inches low at 100 yards trajectory, depending on exact ammunition used. This trajectory is probably flatter than most would expect. My decision to utilize the threaded Lone Wolf barrel is a nod to my future plans to incorporate a suppressor with the Glock KPOS SBR using 147-grain 9mm loads.

Rounds fired quickly rose to over 800 with only a few range visits. It was just too tempting to keep feeding in the Glock magazines. I experienced no failures no matter how quickly or how many 33-round “happy sticks” were fired, which is a credit to the design of the KPOS chassis to not interfere with the mounted weapon’s functioning. A large portion of the Glock slide and ejection portion remains visible following installation, which helps to further prevent reliability issues.

I also tested a DeSantis DSD shoulder holster rig with the Glock KPOS SBR, and although I wouldn’t use it in lieu of an inside the waistband carry, the DSD rig proved a viable concealed method under certain conditions. With the stock folded, the KPOS chassis is smaller than a mini-Uzi, and rides well under the user’s right arm with multiple 33rd magazines carried under the left. However, some may favor discrete off body carry of the KPOS SBR in a backpack or attaché/briefcase with another 9mm Glock handgun carried concealed, thus offering the advantage of same caliber/magazine interchangeability.

The availability of proven Glock factory 33-round 9mm magazines is a huge advantage for the KPOS platform. The KPOS’s folding stock is quick to deploy, and is sturdy once unfolded in the shooting position. However, the two-handed grip afforded by the KPOS’s vertical forward grip, when combined with red dot sight picture, is more than adequate reacting to a situation until the stock can be deployed.

The Sig STS 081 red dot sight certainly assisted in target engagement at close distances, while at the same time increasing accuracy out to 100 yards far beyond normal open sight capabilities. Yes, handguns can engage targets at ranges much further than most realize, but this is not the norm, even under pristine conditions with plenty of time to set up. The Glock’s consistent trigger pull, controllable light recoil, firing from a “closed bolt”, and minimal muzzle blast further accentuated this accuracy advantage. The muzzle blast differential between a 9mm carbine versus obnoxious rifle muzzle signature is further accentuated in confined spaces, such as inside a home if serving in personal defense role.

Although more and more Glock carbine conversion options are appearing in the market, few offer the total Mako KPOS package, which features quality metal manufacturing and folding stock, ease of install/conversion, and picatinny-style rails. Even though a pistol caliber carbine can never be compared across the board to a weapon firing a rifle round (due to effective range and lethality differences of the two cartridges), the KPOS Glock conversion’s portability-to-effective-firepower ratio will trump a rifle’s power in the minds of many users, and it is substantially smaller than many other SBR rifles it was compared to, including an AKSU-74 Krinkov/Suchka, 9mm AR, and SIG556. The KPOS chassis seamlessly integrates the Glock, and there is virtually no compromise in handling or reliability. In fact, a user will have the same positive feel with the KPOS conversion as he or she would with a dedicated PDW or SMG.

Beyond a doubt, the KPOS Glock is much more potent than any handgun due to its increased effective range, and the ability to keep a PDW configured in this manner will undoubtedly outweigh its limitations in the minds of many. A thorough survey of the existing market will reveal few weapon system options matching the Glock KPOS SBR in size, reliability, and capability, especially for the civilian consumer.

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