Glock® Drop-in Trigger Installation
The installation video and instructions provided here are intended to be used as reference by a certified gunsmith during installation.
Installation notes: Ensure weapon is unloaded and no ammo is present for installation. Installation and safety checks should be performed by a certified gunsmith.
Trigger installs the same as a standard glock trigger. The trigger housing includes the addition of a “grail pin” which controls sear engagement effectively eliminating stacking before break. The grail pin is molded into the plastic and captured by the trigger bar when assembled. The trigger bar is fitted for use with this trigger housing. No servicing of the grail pin is required but caution should be used to not break it out during assembly/disassembly of the trigger.
The trigger shoe has been modified to include an over travel adjustment screw. To adjust for over travel, assemble the trigger and function check. With the trigger assembled and slide removed adjustments can be made. It is recommended to adjust to the point where trigger over travel is eliminated but break can still occur when pushing down on the slide near the rear sight. To reduce over travel, turn clockwise. To increase over travel, turn counterclockwise. An additional check for self defense or duty use is to ensure no interference of the firing pin with the safety plunger which could result in light primer strikes with some ammo if not adjusted properly. To check for interference, first dry fire, then gently shake the gun back and forth and listen for the rattle of the firing pin moving freely. At a minimum, firing pin rattling should occur with your finger on the trigger applying minimal pressure. Further over travel can be removed but requires pressure from an inserted magazine either from the slide stop pressure or loaded rounds. This approach is not recommended but can be used if desired, the drawback is no break unless a magazine is inserted and can cause delayed firing if not adjusted correctly and could result in firing pin and safety plunger interference. The over travel set screw has locktite on it but may need to be performed again depending on how much adjustment is made. Be careful when applying locktite to avoid getting any onto the trigger bar, which can cause binding and adversely affect performance. For self defense or duty use, new locktite should be applied to the set screw after overtravel adjustment is made. This is best done by first turning the set screw ½ to 1 full turn counterclockwise then applying a small drop of locktite (red recommended) with a toothpick to control the amount being applied to the exposed threads at the top of the set screw and finally returning the set screw to the correct position noted for overtravel. If adjustment needs to be made after application of locktite it may be necessary to heat the set screw with a lighter for a second or two before making adjustment and reapplying locktite.
The small spring provided is a reduced power safety plunger spring. This spring lightens trigger pull slightly and contributes to smoother pre travel. You can polish your safety plunger or purchase a polished one. A polished safety plunger doesn’t reduce pull weight but smooths out pre-travel grit. Function and safety checks should be performed with the safety plunger you intend to use in the gun. After installation perform the provided safety checks.
Reduced power firing pin (striker) springs can be used to further reduce pull weight. Reduced power striker springs can result in light primer strikes on some ammo. With the standard striker spring, this kit pulls at 3.5 lbs with a polished striker face. It is recommended to polish your striker to get optimal performance with this kit but is not required. If a reduced power striker spring is used it is recommended to purchase a lightened aftermarket striker to increase primer striker reliability.