Last night, I finally had a few minutes of nothing better to do. I took the opportunity to lay out the Rock River Arms AR-15 lower parts kit next to the Spike’s Tactical stripped lower receiver and start actually, you know, assembling the two parts of the puzzle into a more or less complete whole. I thought I’d take a few moments to share some lessons learned last night that I hadn’t seen in my surfing the DIY how to world of AR-15 assembly on the internet.
First, unless you are an experienced gunsmith and/or were trained by the military as an armorer, I highly recommend you spend a little time on YouTube watching the videos of how to actually do the assembly. I found the CMMG, Inc. and Brownells videos to be very helpful, if slightly divergent on order of installation. That is not to say that I don’t have a few minor quibbles with how they present the information.
For instance, if you were to just watch the CMMG tutorial video, you might just believe that the front pivot pin, spring and detent can be easily inserted without tools. Word to the wise, do not attempt this step without the proper pivot pin installation tool unless you enjoy hunting around your work space for an almost microscopic, brass detent. I was lucky. My detent slipped and fell onto the piece of bubble wrap that was lying on the tray I was using as a work bench instead of shooting across the room under spring tension.
I also disagree with the order of installation on both videos. Brownells starts with the magazine release while CMMG starts with the bolt catch. The magazine release really isn’t a bad place to start. In fact, you could argue for it being tied for first with safety selector switch, spring, detent and pistol grip. It is preferable to do the magazine release BEFORE the bolt catch; however, it is required to do the safety selector before you install the trigger group as the safety selector switch will NOT go in if the trigger is already in place (ask me how I know…yes, that’s right, someone had to install the trigger twice) as the trigger partially blocks the safety selector mounting hole (which is proper when you think about it as the safety functions by blocking the hammer from moving up and down). The magazine release is simply a matter of ease of installation. The release is a lot easier to screw in if you don’t have to worry about clearing the bolt catch each time you turn the release into the release button.
Let’s talk about tools for a moment. You’ll notice I didn’t mention anything about a vise block. Brownells recommends using a little hunk of wood or plastic that fits into the magwell opening so that the receiver can be mounted into a vise for easier parts manipulation, etc. Personally, I didn’t find parts manipulation to be an issue (with the exception of the aforementioned pivot pin issue which would not have been helped by the vise block anyway), and I’ve got fairly good sized hands. I do recommend that you go ahead and invest in a non-marring hammer (brass or otherwise). I opted for a lighter weight, steel, claw hammer tapping on a punch set. Fortunately, I didn’t have any errant strikes, but the potential for an ugly tool mark was there. Lastly, unless other manufacturers do things differently, you will need a hex head screw driver with a shaft at least four inches long to install the pistol grip. I have a hex head tool…which is not four inches long making things a tad difficult. I will remedy that after a brief detour into a tool store this evening.
Overall, things went smoothly despite my newbie yet easily correctable mistakes. The trigger and safety selector switch work just fine. The trigger, as you will recall, is a single stage, and it’s a tad heavy. I don’t have a trigger pull gauge, but my guess is that the pull weight is somewhere between five and seven pounds. That is way too heavy for a precision rifle, but this is not intended as such. I am building this one up for home defense, range fun, USPSA carbine matches and maybe the occasional Bambi/wild hog encounter while out walking in the woods. Other platforms will handle mosquito swatting duties out past 100 yards. More important to me a smooth, steady pull and a crisp break. I will reserve judgment on this trigger until the build is complete, and we get a chance to see how it performs at the range. In the meantime, that’ll do Donkey.