Sunday, January 26, 2014

Glock 42 UNOFFICIAL Armorer Update and Glock 26 Comparison

Glock 42 UNOFFICIAL Armorer Update and Glock 26 Comparison 

#Glock42 #Armorer #GSSF

A teardown and comparison, part by part, of the new Glock 42 .380 and a Glock 26 Gen 3, with specific assembly and disassembly tips.  Explanation of steps unchanged from prior models are not provided, only unique instructions are explained.

In The Box

The Glock 42 ships in the same box as the later Gen3 and all Gen4 Glock models.  Two six round magazines are included, along with a lock, manual packet, and a fired casing in dated envelope.  The Glock 42 does not ship with a magazine loader.  The Glock 42 six round .380 magazines are easy to load, requiring a loader even less than the 9mm models.

Field Stripping, Lubrication, and Reassembly

The Glock 42 field strips exactly as prior models.  Once field stripped, the components are the slide, the barrel, the recoil spring assembly, the frame, and the magazine.  Instructions are included in the factory Glock manual.  Glock does not recommend further disassembly by non-armorers.  Lubrication and reassembly are the same as prior models.

Slide Photos

Glock 42 top, Glock 26 bottom - Note revised firing pin safety installed.

Glock 42 right, Glock 26 left - Note clearance for extractor spring loaded bearing and extractor depressor plunger

Glock 42 left, Glock 26 right - Again note clearance

Glock 42 barrel bottom, slide assembly left, recoil spring assembly right
Glock 26 barrel top, slide assembly right, recoil spring assembly left
Note barrel locking geometric similarity and recoil spring assembly similarity

Glock 42 top, Glock 26 bottom - Slide, barrel, recoil spring assembly ready for reassembly, note firing pin safety differences

Barrel Photos

Glock 42 top, Glock 26 bottom - Note caliber markings, proof marks (Georgia on 42)

Glock 42 left, Glock 26 right - Muzzles

Recoil Spring Assembly Photos

Glock 26 left, Glock 42 right - Possible that some non-user serviceable components of this assembly are common between models

Slide Components - Firing Pin Assembly

Glock 42 top, Glock 26 bottom - Dimensions differ, geometry similar

Glock 42 top, Glock26 bottom

Glock 42 top, Glock 26 bottom - Firing pin spring and firing pin spring cups APPEAR to be common between these models

Extractor and Firing Pin Safety

Glock 42 top, Glock 26 bottom 

Glock 42 top, Glock 26 bottom

Glock 42 top, Glock 26 bottom

Glock 42 top, Glock 26 bottom

Glock 42 top, Glock 26 bottom - larger, non-rotating firing pin safety, differs from all prior models, installs only in one orientation due to shape of firing pin safety head

Glock 42 top, Glock 26 bottom - Springs APPEAR common between models

Glock 42 left, Glock 26 right - Firing pin safeties installed


Glock 42 top, Glock 26 bottom - Front sight screws APPEAR to be common between models, note that machining details (relief for screw head) has changed

Glock 42 left, Glock 26 right - Sights APPEAR to be common between models, note that Glock 42 does not have beveling at front edge of slide found on subcompact models

Glock 42 left, Glock 26 right - Glock 42 sight is narrower and appears to be lower.  Channel liner was not removed.

Glock 42 right, Glock 26 (Models 17 through 41 same excluding possible 18) lower left, armorer inspection cover upper left - The inspection cover used on all other models will not fit the Glock 42, either a unique orange armorer inspection cover will be needed or a spare Glock 42 cover can be cut down to inspect engagement.


Glock 42 has only two frame pins, the trigger pin and the trigger mechanism housing pin, similar to early 9mm models.  The trigger mechanism housing pin is removed first, left to right, and differs from prior models only in dimension.  The trigger pin is removed second, left to right, and differs both in dimension and in additional serrations on the left (slide stop lever side).  These serrations appear to serve to locate or secure the new slide stop lever design.

Glock 42 parts left, Glock 26 parts right - Note lack of locking block pin on Glock 42, significant change in design of slide stop lever and spring, change in slide lock spring detent.

The slide lock is removed by depressing it in the middle fully, then pressing it out with the armorer tool from the left side until it can be grasped and pulled out the right side of the frame while covering the slide lock spring to prevent its loss.  The slide lock spring is not captive.  To reassemble, seat the slide lock spring, depress it with the armorer tool, insert the slide lock from the right side so that it captures the spring and press it through to its normal position.  Remember that the barrel groove on the slide lock should be up and to the rear so that the part number is readable from the shooter's point of view.

Glock 26 right, Glock 42 left - Slide lock spring

Glock 42 right, Glock 26 left - Slide lock spring in frame

Glock 42 top, Glock 26 bottom - Slide lock installed

Slide Stop Lever and Assembly/Disassembly Change

Detail of Glock 42 slide stop lever installed and trigger pin - Note differences in lever and pin, and additional grooves on trigger pin

Glock 42 top, Glock 26 bottom - On Glock 42, slide stop lever is removed after the locking block and installed before the locking block

Magazine Catch

Glock 42 right, Glock 26 left - Glock 42 magazine catch functions, removes, installs just like Gen4 Glock models and can be installed for right hand or left hand use.  Magazine catch spring was not removed but appears to be identical to part #280 used in other models.

Trigger and Related Components

Glock 42 top, Glock 26 standard middle, Glock 26 NY1 and - connector bottom

Glock 42 trigger bar bottom, Glock 26 trigger bar top - Note lack of tab on cruciform of Glock 42 trigger bar since S spring is not used, Glock 42 trigger is smooth since GCA 1968 import points are not relevant for US manufactured pistol

Glock 42 trigger mechanism housing, trigger spring, connector (the short one) center.  Glock 26 trigger mechanism housing upper right.  Glock S spring shown above stock Glock 26 connector, NY1 olive trigger spring shown above Glock - (dash) connector

Note Glock 42 connector, though smaller, has the same geometry as the stock connector on other Glock models

Glock 42 top, Glock 26 bottom

Glock 42 right, Glock 26 left - Connectors removed for clarity, note bottom detail of Glock 42 trigger mechanism housing is similar to 9mm Gen4, note orientation of trigger springs

Glock 42 right, Glock 26 with NY1 left - Trigger mechanism housings complete

Glock 42 left, Glock 26 stock center, Glock dash right

Glock 42 left, Glock 26 stock center, Glock dash right - Note similarity of angle between Glock 42 and standard weight Glock connector (center)

Important Reassembly Change

My 2012 Glock Armorer's Manual states "Reinstall the trigger bar and ensure the left arm of the cruciform goes on top of the drop safety ledge of the trigger mechanism housing" (page 54).  Most of us learned to do this by "rotating" the trigger bar into the housing, which is easier than normal when using a New York spring.

Glock 26 trigger bar installed with NY1 spring in trigger mechanism housing

On the Glock 42, however, it is critical that the front edge of the cruciform be captured by the "hook" on the trigger spring.  If the cruciform is not captured by the hook, the trigger does not reset.  (Tested dry firing, assumed but not confirmed with live fire).  

Two views of the Glock 42 trigger spring hook properly capturing the trigger bar cruciform

Apparent Trigger Options

Glock 42 trigger mechanism housing and trigger spring

The Glock 42 trigger spring can be installed with the foot of the spring in either of two different detents recessed into the trigger mechanism housing.  The illustration showing the trigger mechanism housing in blue, the trigger spring in green, and the hook of the trigger spring in red show that the two positions change the leverage of the spring as it aids the trigger bar moving back against the firing pin and spring under pressure from the trigger.  

I observed a lighter trigger pull with the trigger spring installed in the upper position and a heavier pull in the lower position.  I have not quantified the difference.  

Update 3/1/2014 - GSD17 on and others have caused me to rethink the second spot for the foot of the spring, and convinced me that the upper spot is a disassembly aid only.  


I forgot to take one apart, but at a glance they appear to disassemble and reassemble like all prior.  The magazines have notches for left hand and right hand mag catches.


The Glock 42 components in general appear to be appropriately scaled down from larger models with only five exceptions

1 - Slide lock spring

Change from irregular leaf to coil, probably a cost savings and to aid ease of assembly, disassembly.

2 - Slide lock

Slight beveling of spring detent to accommodate disassembly procedure change necessary for coil spring.

3 - Slide stop lever

Change to spring, appears to make inadvertently misassemble more difficult.  Prior versions could be installed with the slide stop lever spring oriented incorrectly relative to the locking block pin, resulting in a slide stop lever that locked back after every round.  Change to spring requires that the slide stop lever be installed prior to the locking block.

4 - Firing pin safety

Larger and non-rotating.  Occupies the entire path of the nose of the trigger bar, perhaps so that position of trigger bar nose left to right is less critical and the locating bump found on later trigger bars is not required.

5 - Trigger Spring

A significant change to the spring and its assembly, providing multiple trigger pulls with no change in parts, only a change in reassembly orientation.

I expect to see all five changes in future revisions to existing Glock models.

Comments welcome and I'll credit significant revisions.  

1/26/2014 - Sam Shallenberger - Copyright © 2014

NRA Instructor, TN Handgun Carry Instructor, Glock Armorer, Certified Merger & Acquisition Advisor, Certified Lease Professional, Bunburner 1500 Gold rider, C&R FFL, N8ZTE, MBA, MACC

2/3/2014 - Added detail photo below of Spring Loaded Bearing to address Mike's comment.  Spring loaded bearing now appears to have a molding dimple on the slide cover end.  I've not noticed this in the past, the Glock 42 may or may not be the first with this change.