ABOVE: GLOCK offers users a choice in handguns chambered in 10MM Auto in the form of G29, G20, G40 MOS.
Full stable of 10MMs with the G20, G29, G40 MOS
GLOCK has made noteworthy additions to their product line at the last two SHOT Shows. The GLOCK 4040 (G) MOS 10mm is an excellent example of this. In effect, the G40 MOS is a long slide 10mm Auto with 6 inch barrel combined with means of mounting a variety of red dot optics on its slide. The G40 appearance coincides with a recent up surge in handguns being chambered in 10mm Auto. Only Freud could provide analysis of why so many are deciding to explore the 10mm Auto; better late to the party than not showing at all considering the 10mm’s up and down history. GLOCK has been a 10mm standard bearer since the early 1990’s with introduction of the G20 and G29; each of which has been in constant production since. The introduction of the G40 MOS further shows GLOCK’s support of the 10mm Auto.
In firearm circles Jeff Cooper is given the most credit for the early development of the 10mm Auto. Yes, other .40 caliber pistol wildcats had been in existence. However, the 10mm Auto is the one that achieved the most commercial success. The 10mm Auto was designed to be a rimless semi automatic pistol cartridge with magnum power associated with the .41 Magnum. The ill fated Bren Ten was chambered in 10mm Auto. Fortunately, other manufacturers such as Colt and GLOCK picked up the 10mm Auto mantle keeping it viable. The brief FBI flirtation with the 10mm Auto also raised its profile within the shooting community. The 10mm Auto story must be finished by stating that the .40 S&W eventually emerged from and succeeded the 10mm Auto becoming a pre-eminent personal defense and law enforcement cartridge. In short, no pun intended, the .40 S&W is a reduced length and powered 10mm Auto. The .40 S&W case is 3mm shorter than the 10mm Auto’s 25mm case length. All of this came about as a result of the recoil of the full powered 10mm Auto causing consternation among certain law enforcement personnel and trainers.
Many detractors would have you believe that GLOCK has grown complacent by not introducing any “new” designs that depart significantly from the template laid by G17’s arrival in 1982. This is not correct considering Fourth Generation of refinement combined with multitude of calibers and frame sizes offered. The 10mm G40 MOS a perfect example of this. Yes, GLOCK is reacting to current market trends showing a propensity for using miniature red dot sights on handguns; still does not detract from fact of making such an option available. The stout GLOCK platform has proven an ideal companion to the 10mm Auto chambering from the start.
The 2010 SHOT Show was the “official” presentation of the Fourth Generation GLOCK. The 4th Generation GLOCK reflects a combination of both ergonomic and internal changes. Many will point to GLOCK finally acceding to market demand by offering interchangeable backstraps of different sizes with the 4th Generation introduction. It is suspected the increasing amount of competitors offering the ability to change grip sizes was making too many inroads into both the law enforcement and civilian markets. Grip sizes are small, medium, and large frame. Grips are changed via removing a single pin. The Gen 4 comes with the small grip frame molded the frame with the medium and large grips fitting over the frame as a user sees fit. Along these same lines 4th Generation GLOCKs receive a modified rough texture frame and grip texturing. Basic grip size is smaller with the 4th Generation introductions with the GLOCK backstrap “hump” lessoned along the lines of the previously introduced Short Frame (SF) 3rd Generation GLOCKs. This aids shooters with smaller hands by reducing the circumference of the grip frame. The medium grip size of the 4th Generation GLOCK can be likened to the grip found on 3rd Generation GLOCKs. The magazine catch on the 4th Gen GLOCK is enlarged and reversible requiring no additional parts to do so. 4th Generation GLOCKs come with three (3) magazines configured with the cutout catches on either side of the magazine body. All previous GLOCK magazines will work with the 4th Generation GLOCK as long as the magazine catch is configured on the frames left side.
The G20 10mm is the “standard” sized GLOCK resembling a muscled up G17 with 8 inch length and 1.27 inch width (G17 is 1.18 inches wide). The G20’s hexagonal rifled barrel (more on this later) measures 4.6 inches. The Gen 4 G20 variant arrives with three (3) 15 round magazines. The G29 10mm is the more compact variant measuring 6.88 inches in length thanks to 3.7 inch barrel. Width is 1.27 inches. The G29 features 10 round magazines, though the 15 round G20 magazines will fit as well. The G29’s size offers compact size, roughly analogous to 1911 Commander, with superior capacity and firepower. The last tale of the tape will focus on the new G40 MOS. It is a true “long slide” reminding one of 17L dimensions. A length of 9.5 inches provides extended sight radius. G40 MOS width is 1.27 inches. The 6.02 inch barrel gets the most out of the 10mm Auto in terms of velocity.
10mm Auto ammunition from Federal, Buffalo Bore and Hornady was accessed for use in the 10mm GLOCK handguns. Buffalo Bore is a prime source of true 10mm Auto ammunition offering several bullet types ranging from hard cast, JHC, to FMJ-FN. Buffalo Bore hard cast bullets are not verboten with the GLOCK hexagonal rifling. This goes against typical warnings related to lead bullets. This is because of the differences between soft lead “cowboy” bullets and hard cast bullets. True hard cast bullets (as opposed to lead swaged bullets) that are properly lubed will not lead foul hexagonal barrels any more than any other type of rifled barrel. Hard cast bullets are not “lead” bullets as most associate with the term. The Buffalo Bore hard cast loads are an excellent option for anyone contemplating using the 10mm Auto for hunting.
Premium 10mm Auto loads from Hornady were used consisting of 155 grain XTP and 175 grain FlexLock Critical Duty. These Hornady loads were designed with personal defense in mind with XTP and Critical Defense bullets loaded to 1150 to 1250 fps. The Critical Duty’s FlexLock bullets have a heavy jacket and a harder, high-antimony core designed to defeat barriers. The jackets are locked to the core via the same InterLock process the company uses on its centerfire rifle bullets. Hornady has also taken full advantage of recent advances in propellant technology use low muzzle flash powder in Critical Duty ammunition. Hornady Critical Duty FlexLock bullet balances barrier penetration with proper expansion in the target for maximum effectiveness. Hornady Critical Duty passed all five of the FBI’s barrier criteria tests giving 12 inches plus of penetration no matter if through glass, sheet metal, heavy clothing, drywall, and plywood while still expanding for maximum wound channel as well as not passing through the ballistic gel test medium. FlexLock bullet nose prevents the hollowpoint from deforming or clogging when passing through barriers. The ogives of the Critical Duty bullets do not taper as much as compared to other hollowpoints bullets, which improves feeding characteristics in autoloaders. The nickel plated cases are another attention to detail nod that limits drag into or out of a weapon’s chamber limiting chance for failure to feed or extract. Critical Duty, as the name implies, was designed for law enforcement in mind. However, security conscience citizens would be amiss not to at least consider it for use as well.
Another positive associated with any GLOCK product is the availability of supporting products, especially when it comes to holsters. BlackHawk! and Galco holsters were chosen to support the GLOCK 10mms during T&E sessions. Much anticipation awaited firing the three GLOCK 10mms in terms of recoil and muzzle blast. Range T&E took place at Echo Valley Training Center (EVTC). The Federal Vital Shok 180 grain Trophy Bonded 10mm Auto and Buffalo Bore were the stoutest loads, but in no way harsh or unmanageable. Anecdotally, empty brass was ejected briskly several feet away such was the slide velocity. The GLOCK polymer frames were appreciated for absorbing and mitigating felt recoil. Even the more compact G29 proved no problem. EVTC TacStrike steel targets were rocked with a more substantial smack than a typical handgun round. While one was definitely aware you were not firing a 9mm, recoil was not prohibitive with accurate rapid shots possible. As anticipated the larger G40 MOS was the smoothest. All of the 10mm Auto loads tested had no issue penetrating windshield or car body sheet metall. This is the type of performance and barrier penetration capability that the 10mm Auto was designed for. Further range testing consisting of dumping multiple magazines at several targets in rapid fashion.
Each GLOCK was tested fired through a chronograph to determine the effect of barrel length on velocity per specific load. Velocity gain between the 3.7 inch G29 and 6 inch G40 MOS was in the 100-120 feet per second range. For example, the Buffalo Bore 180 grain JHP clocked in at 1320 fps from the G29 and 1445 fps from the longer barreled G40 MOS. The Hornady 155 grain XTP chronoed 1242 fps from G29, 1309 fps with G20, and 1406 fps out of the longer barreled G40 MOS.
EVTC facilities were taken advantage of when evaluating the G20, G29, and G40 MOS by working in, around, and thru range vehicles. IPSC cardboard targets were placed within vehicles so that the 10mm Auto power could be judged thru automobile sheet metal, side glass, and windshield. In conjunction with this targets were arrayed in front of a range vehicle with the GLOCKs used to engage through the windshield from the front seat.
The G20 sights were left factory standard with TRUGLO TPX sights installed on the G29. The TRUGLO TPX iron sight combines fiber optic with tritium. This enhances visibility in daylight as well as at night. The TPX sights are CNC machined from steel for durability. The G40 MOS’s ability to mount red dot optic was taken advantage of by mounting a Trijicon RMR. This approach allowed an exploration of the different sight systems. The standard GLOCK factory sights are a known commodity and serve their purpose. There is no doubt that the TPX sights draw your eye to the front post; something most firearms instructors advocate for effective aiming. TRUGLO has further reinforced this by installing a white locking retention ring on the front sight to contrast with black retention rings around the two vials in the rear sight. The rear TPX sight is wider compared to a standard sight allowing for daylight around the front sight for more precise aiming and allowing for easier tracking of the target. A six o’clock hold produced tight groups at 15 yards seemingly on top of the front post. The TRUGLO sights stayed solid after hundreds of rounds fired with the G29. The TPX sights are a definite performance enhancement worthy of considering for retrofitting other carry handguns with.
The RMR equipped G40 MOS came into its own for precise fire at any range desired with placing the dot on the target and applying correct trigger control. The G40 MOS demonstrated the ability to hit steel man popper targets at 50 yards with amazing efficiency and even out to 100 yards with regularity. Speed drills involving plate racks and dueling trees were run with times more similar to a pistol caliber carbine than a handgun. The advantage offered by use of red dot sights in the competition environment is well known. The ability to place the RMR dot on the plate and not having to align front and rear irons proved adept at moving rapidly from plate to plate. The G40 MOS was also fired using the standard adjustable GLOCK sights that arrived on it. As expected the longer sight radius proved beneficial.
The inherent familiarity most have with the GLOCK platform, not to mention its ergonomics, validates anyone’s decision to chamber it in 10mm Auto. It is best to think of the GLOCK line-up of handguns as a “system” stretching from the mini G42 thru the G40 MOS. This was quickly evident when handling the G20, G29, and G40 MOS. While the balance and weight may change between each, the position of the slide and magazine releases will instantly be familiar. The key here is the similar trigger pull and feel found on the GLOCKs. Simplicity should not be confused as lack of refinement. As experience and knowledge expands, GLOCK reliability and solid performance has become more entrenched as the standard. There are many tactical situations in which the penetration and power of a 10mm Auto fired from a GLOCK type weapon could be very advantageous. Is the GLOCK 10mm Auto a prime weapon for all situations or users? Of course, not; however as a duty, personal defense or hunting handgun it is hard to beat thanks to powerful chambering and superior capacity. All of the GLOCK 10mms places real power in an accurate and reliable handgun package. The ability to reliably engage targets out to 100 yards was a pleasant surprise; the red dot equipped G40 MOS greatly expands assumptions about handgun effective range pushing the handgun operating envelope. The GLOCK G20 and G29 represent good balance of features for daily use as a duty or concealed weapon. After all, at its origin the 10mm Auto was designed specifically as a fighting cartridge. Each of the 10mm Auto GLOCKs allows a user to indulge oneself by having something out of the ordinary, while maintaining
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Buffalo Bore Ammunition