Hammer & Trigger Pins (2)
Hammer Hammer Spring (the larger of the two similar springs in the kit)
Trigger Spring (the smaller of the two similar springs)
Disconnector Spring (this is similar to the bolt-catch spring, but it is identifiable because one end is wider than the other)
Small, non-marring Hammer
5/32 pin punch (Optional)
Insert the trigger assembly into the receiver and align the hole with the back one of the two pin holes in the receiver. You will have to push on the trigger and/or disconnector assembly to compress the springs and help align the holes for the trigger pin. It helps to use a straight-sided 5/32 pin punch as a slave pin to keep everything in alignment before installing the trigger pin. (Of course, doing so will drive out the slave pin.) The trigger pin has two grooves in it, but it doesn’t matter which way it is inserted. The accepted method is to push it left to right, with the groove on the left side.
Cock the hammer. Pull the trigger and make sure it releases the hammer. (Do not let the hammer hit the receiver in the process.)
Keep holding the trigger back. Push the hammer back and the disconnector should catch and hold the hammer. Releasing the trigger should cause the disconnector to release the hammer, which should then catch on the trigger sear in the cocked position. Repeat this test several times to ensure the trigger, hammer and disconnector are all working properly.
Unparsimonious Potential Upgrade
Alas, traditional mil-spec AR triggers aren’t known for being crisp, clean-breaking or for anything resembling precision accuracy. Fortunately, there are a handful of manufacturers out there, like Geissele , Jard, Performance Firearms, Timney an Wilson Combat that offer aftermarket alternatives sporting modern refined designs, including user-adjustable pull weights and one-piece modular construction to facilitate easier installation. I selected a Performance Fireamrs Hipertouch 24 Trigger for my build due to its dual overtravel toggle springs that successfully offset the high-sear-impingement force commonly found in traditional offerings.
For those looking for a more economical alternative, JP Enterprises offers a reduced-power spring kit for target, hunting or competition ARs that replaces factory trigger springs. While they will not eliminate the gritty stock-trigger feel, they will significantly reduce creep and pull weight on a rifle’s trigger. But, be aware, they springs do wear out faster than normal and as such the company doesn’t recommend using them for defensive rifles.
The next entry will cover installing the grip and the Fire Control Selector, otherwise known as the safety.