Trigger Safety checks (DO NOT SKIP THESE STEPS): These safety checks are applicable to any Glock® trigger, stock or aftermarket, and should be performed regularly to ensure all safeties are functional. Ensure weapon is unloaded and no ammo is present for safety checks. Many aftermarket triggers can fail to be firing pin safe but do offer some level of compromised drop safety.
- Check trigger safety to ensure it is engaged when weapon has been racked. Without engaging the trigger safety bar firmly press the trigger to attempt firing. Ensure that the trigger safety does not slip off resulting in firing. If slipping occurs your weapon is no longer drop safe or firing pin safe, ensure it is repaired before use.
- With the slide removed and trigger installed pull trigger forward so that it is resting on the trigger safety. Press the trigger bar on the cruciform at that trigger housing. Ensure that the trigger bar will not drop in a manner that could result in striker release. If the trigger bar drops into the housing, your weapon is not drop safe, ensure it is repaired before use.
- With the slide assembled but back plate removed and striker not engaged with the trigger bar, pull the trigger forward so that it is resting on the trigger safety and ensure that the firing pin is blocked and cannot move forward. This is best done using a Glock armorer’s tool and pressing the rear of the firing pin firmly with the armorer’s tool to ensure the firing pin cannot slip past. If the firing pin can slip past the safety plunger, your firing pin safety is not functional. Ensure your trigger is repaired before use. Finally pull the trigger and ensure the firing pin moves freely past the safety plunger. If firing pin is felt to be impacting or slipping by the safety plunger, this can sometimes result in light primer strikes and should be repaired or over travel adjusted before duty or self-defense use. The easiest way to check for safety plunger interference is to perform the “rattle test” described in the installation notes.
- Install a Glock armorer's back plate or look underneath the standard back plate and check for 2/3 to full firing pin to trigger bar engagement (sear engagement) when firearm is racked. As an additional reliability check, check sear engagement on reset while holding trigger depressed. Sear engagement on reset should be closer to 3/4 to full engagement to ensure long term reliability.