Glock 43X MOS may be available with the Shield RMSc sight already installed but it is good to know how to mount the red dot sight on the handgun if yours didn’t come with it or if the sight became loose during some use as it happened to the author.
About Glock
Gaston Glock founded Glock back in 1963, but initially, the factory didn’t make firearms. When Mr. Glock accidentally learned that the Austrian army will soon be procuring a new service pistol, he consulted experts and consolidated their recommendations into a list of features that would be desirable in a modern pistol and compared this list with the army’s requirements. Utilizing modern production methods including polymer injection molding Glock managed to produce prototypes that outperformed eight other pistols submitted for testing and the new Glock pistol designated P80 became the service pistol of the Austrian Army in 1982. The Pistole 80 had to prove it was capable of firing 10,000 rounds with less than twenty stoppages. Its magazine held more than twice the required number of cartridges – 17. Coincidentally, this number soon became the pistol’s model designation since it included the 17th patent granted to Gaston Glock.
Glock 17 wasn’t the first polymer-framed pistol that was serially manufactured but it was the first that became globally accepted. Glock pistols generally consist of only 33 (or 34) components. Since they contain only two (or three) pins and no screws, they can be completely disassembled with just a simple punch and any part can be replaced within minutes without any adjustments. Glock has introduced many models since their first pistol maintaining the now iconic design almost unchanged and achieving leading position in the handgun industry over the years.
About Glock 43X slimline MOS
Glock 43X MOS is a mid-sized micro-compact slim RAIL and slim MOS equipped pistol. It is manufactured in Austria, Europe, by the Glock company. It has a longer and somewhat wider grip-frame than its predecessor Glock 43 maintaining the same length of barrel and slide with a benefit of front serrations added. Glock 43X MOS boasts Glock’s legendary safe-action striker-fired system where striker only cocks partially when the chamber is loaded and trigger includes a safety latch, making it one of the safest pistols to carry. Glock 43X MOS comes with two single stack 10-round magazines which is admittedly on the lower end of mid-sized micro-compacts offered today but the pistol definitely justifies its slimline designation with a narrow slide measuring mere 22 mm (0,87 in) and maximum width at the grip measuring 28 mm (1,10 in). Since Glock is also a pistol brand with the most extensive after-market offering, higher capacity magazines are available for Glock 43X MOS (such as 15 or even 15+3 rounders).
Glock 43X MOS comes prepared for mounting an optical sight and other after-market equipment.
The pistol has a longer grip than its predecessor Glock 43 increasing its firepower to 10 +1 cartridges and making it more comfortable to shoot.
The handgun is available in the 9×19 caliber. Factory and aftermarket threaded barrels are available for the Glock 43X MOS.
Glock 43X MOS is optic ready for specific optics (RMSc/SMSc mounting standard).
Cover plate protecting the slide cutout is located in front of the rear sight of the Glock 43X MOS.
Optic ready properties of GLOCK 43X MOS
Glock 43X MOS has an optic cut that measures 41 mm in length and 22 mm in width (slide width).
The design of the optic cut on this handgun is made to accommodate a red dot sight with a Shield RMSc/SMSc mounting standard mounted directly to the slide. No adapter plates are necessary for mounting the optics with a footprint that is compatible with this standard and none are available from manufacturer. With a Shield RMSc/SMSc mounted, the pistol’s factory sights may still be used enabling co-witnessing of the red dot through the optic’s window.
Glock 43X MOS optic cut fits the Shield RMSc footprint perfectly but will also accommodate standard Shield SMS sight (and sights with matching footprint) as well (note the rear cutout contour for the very familiar mini sight “dimple”).
As an option pistol is offered factory equipped with a Shield RMSc red dot sight.
Red dot sights using standard Shield RMS/SMS mounting standard may also fit the Glock 43X MOS optic cut since it has the same studs/holes layout as the RMSc/SMSc mounting standard. You should verify that they also fit into the slide cut and be aware that the sight will probably somewhat overhang the slide on both sides.
Glock 43X MOS includes a slim accessory rail molded into the dustcover which allows mounting of other specific accessories such as weapon mounted lights and lasers. The slim accessory rail does not accept most of the standard accessories intended to be mounted to a Picatinny-type (MIL-STD-1913) interface rail. Equipment designed specifically for slim accessory rail must be chosen to allow proper attachment (such as Surefire Xsc, Streamlight TLR6, TLR7sub, TLR8sub).
Recommendations for mounting the optical sight on a pre-cut Glock 43X MOS slide
Never proceed with any firearm handling without performing the clearing/checking procedure – magazine is removed, chamber clear.
Always clear the firearm and complete the safety check before proceeding with any work or adjustment on the pistol. Field strip the handgun removing the recoil spring and the barrel from the slide as indicated in the Glock instructions for use. To facilitate easier mounting of the optical sight, place the slide of your pistol on a flat surface making sure that the recoil spring guide ring overlaps the surface.
Placing the slide of the Glock 43X MOS pistol on a flat surface with the recoil spring guide ring over the edge will make your job easier.
Remove the Glock cover plate. Two M4x7.5 TX10 Torx head screws are used for the cover plate. OEM screws come with a drop of non permanent thread glue applied. Only use original screws for re-attaching the cover plate if you decide to use the pistol without an optical sight. Do not fire the Glock 43X MOS pistol without either the original cover plate mounted or an optical sight installed.
Use the Glock supplied or other Torx TX10 wrench to remove the screws from the MOS cover plate.
Following manufacturer’s instruction for mounting a specific optical sight is always highly recommended. Before mounting the optical sight, clean and degrease the interface cut in the slide.
Removing the slide cover plate from the Glock 43X MOS slide.
Clean the threaded holes and mating surfaces thoroughly. Do not skip this task. Note there is an internal component (extractor plunger & spring assembly) visible through one of the mounting holes – screw must not reach it.
Thoroughly clean and degrease the threads and all contact surfaces in the slide cut. Once you cleaned and degreased everything, attach the chosen optical (red dot) sight with the RMSc/SMSc mounting standard to the pistol and verify that it fits into the slide cut. Thread the fasteners (screws) in until they seat, without torquing them down. Use manufacturer supplied or high quality M4x8 mm flat-headed screws to mount a Shield RMSc sight to the Glock 43X MOS pistol. When mounting other compatible optical sights, ensure the screws do not extend more than 3 mm through the bottom of the sight body prior to installing the sight. If the screws are too long for the specific optical sight, they may cause damage to the weapon and/or may cause malfunction. If the screws are too short on the other hand, the sight might not be attached properly which may also cause damage to the slide and/or may cause malfunction.
Insert the battery into the sight and check its function (if it is bottom mounted – shown with the Shield protective sticker applied, positive terminal towards the slide). Verify the sight fits the slide cut.
Position the sight on the slide and press it down verifying it can be pushed flat against the cutout without extensive force.
Insert the fasteners (screws) into the optic’s mounting holes and verify they do not extend more than 3 mm from the bottom of the optic body.
Do not use threadlocker yet. Carefully start the screws taking care not to miss-thread them. Seat them without tightening. Check for any movement, gaps under the sight or uneven positioning prior to properly torquing the screws.
After seating the screws and prior to torquing them completely, check if there is any noticeable movement when trying to move the sight. If so, back the screws out partially, ensure the sight is positioned properly and re-seat them. If the screws are seated all the way and there is still movement, the fasteners are too long. Replace or shorten the screws that are too long or use appropriate washers to ensure correct fit. Consider the possibility that the chosen optical sight might not fit the slide cut of the Glock 43X MOS pistol.
Remove one of the mounting screws and apply a small amount of non-permanent (blue) threadlocker to the protruding part of the screw covering the threads. Replace the screw and seat it prior to removing the other one in order to repeat the process.
Tighten both screws gradually, alternating from one to the other until the specified torque is reached using a torque wrench.
If the sight has proven to fit, remove one of the fasteners and apply the recommended non-permanent threadlocking compound. Blue adhesive such as Loctite 243 or 248 is a good choice. If you use a permanent threadlocker, getting the optic off the slide at a later time is going to be difficult and might require heating the fasteners. There is no need for using excessive amounts of adhesive, just a drop spread across the threads will do. Rethread the fastener until it stops and repeat the process with the other one. Gradually torque both screws alternating from one to the other until the torque specified by the optic manufacturer is reached using a torque wrench (typically 1,5 to 2 Nm or 13 – 18 in-lb). You can also hand tighten each fastener by inserting the short end of the L-shaped Allen or Torx key into the socket head then turning it clockwise till slight flex is felt in the key. Do not overtighten. The pistol should not be test fired for at least a few hours after mounting, allowing threadlocking compound to cure.
If a torque wrench is not available torque each fastener only until a slight flex is felt in the long arm of the L-shaped Allen key. Do not overtighten.
It is a good practice to mark the heads of the fasteners and the optic housing to enable rapid user verification for possible loosening of the fasteners that could lead to the optical sight failure.
Glock 43X MOS equipped with a Shield RMSc red dot sight and a Surefire XSC micro-compact weaponlight (folder pictured below is Spyderco’s Microjimbo).
How to sight in (zero) the Shield RMSc mounted on a pistol (coming soon)
Red dot sights that can be mounted directly onto the optic cut of Glock 43X MOS
No adapter plates are included with the Glock 43X MOS pistol. If you wish to mount a red dot sight that does not use the Shield RMSc/SMSc mounting standard, a suitable converter plate is required.
Converter plate mounting options
Note: Using a converter plate results in a higher-profile setup of the red dot sight. Iron sights co-witness may become an issue.
Shield RMS below, Noblex (Docter) above
These plates allow the user to convert the mounting surface, making it suitable for attaching red dot sights that use the Docter/Noblex mounting standard. (Coming soon!)
Shield RMS below, Trijicon RMRcc above
These plates allow the user to convert the mounting surface, making it suitable for attaching red dot sights that use the Trijicon RMRcc mounting standard. (Coming soon!)
Shield RMS below, C-more above
These plates allow the user to convert the mounting surface, making it suitable for attaching red dot sights that use the C-more mounting standard. (Coming soon!)
If you manufacture adapter plates for this pistol and are interested in cooperation with us, send an e-mail to info@optics-trade.eu
