AR Lower-Receiver Build: Grip and Fire Control Selector Installation

posted on October 16, 2015
The necessary parts and tools are listed below:

Safety (called the fire-control selector in AR jargon)
Fire Control Selector Detent Fire Control Selector Spring. (this is similar to the pivot/takedown detent springs, except there are two of them and only one fire-control selector spring—look them over carefully and you can see the difference)
Pistol Grip
Pistol Grip Lock Washer
Pistol Grip Screw

Screwdriver or Allen wrench to match the grip screw

Insert the safety from the left side of the receiver. (When I attempted this, the selector was impinging on the top-rearward portion of the trigger, so I had to drift out my trigger pin and use my finger to press down on the trigger to create enough clearance to install the selector. Once in place, I used a slave pin to align everything until the trigger pin slid back in place.) Check to see that the selector turns freely and that it locks the trigger so the hammer will not release when in the "safe" position.

With the safety selector in place, turn the receiver upside down and place the detent in a hole located on the left-rear portion of the receiver.
Next, turn the receiver upside down. Insert the detent into the small hole at rear of the trigger guard on the left side of the upside down receiver. Insert the spring in the hole in the pistol grip and install the grip, aligning the spring with the detent and the hole in the receiver. Make sure the selector is in the off/"fire" position. Carefully push the grip in place while compressing the spring. Secure the grip in place with the screw and washer. Most are slotted for a screwdriver, but some require an Allen wrench, which I find easier and highly recommend. You may want to put a drop of #242 blue Loctite on the screw.

A small channel in the top of the grip is where the safety selector spring goes. Take care to make sure the spring is in line with the detent prior to tightening the grip screw.
Function Check
Turn the selector to make sure it rotates to the "safe" and "fire" positions and that it locks into those positions. Note that the hammer must be cocked for the safety to move to the on position. Check again to ensure the safety is preventing the trigger from releasing the hammer, by putting the safety on and pulling the trigger forcefully, multiple times. Push off the safety and verify that the hammer stays cocked. Verify the trigger will release the hammer when the lever is in the fire position.

Unparsimonious Potential Upgrade # 1
I am not a fan of the traditional AR safety selector due to its narrow paddle, which makes actuation difficult under the best of circumstances. As an alternative I opted to substitute the Blackhawk Offset Safety Selector. Besides being a southpaw shooter, the component can be found on most of my ARs and it’s my go-to choice for ARs because, despite its size, it has a lot going for it. The part contains a built-in 45-degree offset, which translates to a shorter travel and lessens the range of motion required for actuation and keeps your hand wrapped around the pistol grip where it suppose to be. Furthermore, the paddles feature a larger profile to offer easier access and purchase. My southpaw affliction aside, I prefer the component because it fosters enhanced ergonomics that allow the shooter to actuate the safety with either hand—without compromising your firing grip.

Unparsimonious Potential Upgrade # 2
Regarding the pistol, like Towsley, I don’t care for the traditional plastic M2-style grip either, and almost followed suit selecting Hogue Rubber grip he selected—but I decided against it. The rubber texture would undoubtedly lend itself to my gloved hands during hunting season by offering ample purchase, but the added bulk in the gloved fingers may not align quickly with the finger grooves, so I decided choose a TangoDown Battlegrip. In addition to offering a built-in palmswell to fill the hand, the sides contain an aggressive, non-slip surface without the need for finger grooves. Finally, like the aforementioned Blackhawk safety selector, the Battlegrip is another one of my go-to parts. There’s something to be said for familiarity and pre-established muscle memory.

The next entry will cover installing the magazine release.


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