Assembling an AR-15 lower is easier than I expected!

[electronics]

A couple of weeks ago I decided to build my first AR-15... then promptly decided to use an assembled upper. My lower parts kit came in yesterday so I got to work. Barring a couple of finicky steps, it was much easier than I thought it was going to be. I had read some peoples' recommendations for roll pin holders and everything else on a few forums, and on these same forums people saying you don't need all those specialty tools. The only tools I ended up using were a set of vice grips, a tack hammer, a larger hammer (to hit the tack hammer...), and a castle nut spanner wrench.

I ran into a few difficulties. Getting the roll pin started for the bolt catch proved troublesome, but I eventually got it going with the vice grips (which resulted in a little bit of marring on the lower where the bolt catch touches on one side, as I was getting a bit frustrated with it and didn't mask the part of the lower the vice grips were in contact with). Getting the trigger assembly pin in was a bear, mainly because it seemed like the sear hole would not line up--in actuality I just needed to tap the pin with a hammer, and once I did this it went in in about 30 seconds. The hammer pin wasn't nearly as difficult, though. I also lost track of the buffer retention pin and spring for a short period of time; 'smithing' in a room with gray carpet is not the best idea, but keeping a flashlight handy makes finding little springs a lot easier. Other than those couple issues, everything went quite smoothly!

I just thought I'd share my experiences in case someone has thought about it but been nervous. It is extremely easy, much easier than I thought it would be! I used this guide for the whole process. It's slightly confusing on a couple of steps but overall is quite thorough and easy to read.

Now I just need the last couple parts to get here... My grip is currently en route, so until then my safety selector detent and spring are lonely in the bag. I've replaced a grip on an AR-15 before and know this step is simple, as long as you know there is a spring and detent being held in place by the grip.


Anybody have anything to add? Tips for getting the bolt catch roll pin started?

[hertz]

I launched my front takedown detent accross the room on my first lower. Never did find that thing. I ordered two just in case.

As far as the bolt catch roll pin goes. Start it with vice grips or pliers and then tap it with a small hammer the rest of the way. Make sure everything has a hefty coat of tape.

[arjohnson]

I probably built a couple dozen lowers and they are really not that hard, just take your time.

[arjohnson]

I launched my front takedown detent accross the room on my first lower. Never did find that thing. I ordered two just in case.

As far as the bolt catch roll pin goes. Start it with vice grips or pliers and then tap it with a small hammer the rest of the way. Make sure everything has a hefty coat of tape.

Great advice.

That's exactly how I do it, works great. I actually squeeze the pins in as far as the channel locks allow, then tap in a little with the punch and it's done, no idiot marks..

[BerksCountyDave]

IMO, assembling an upper is easier than assembling a lower.

[LittleRedToyota]

I eventually got it going with the vice grips (which resulted in a little bit of marring on the lower where the bolt catch touches on one side, as I was getting a bit frustrated with it and didn't mask the part of the lower the vice grips were in contact with).

another technique to prevent marring is to wrap the jaws of the vice grips with electrical tape.

[electronics]

another technique to prevent marring is to wrap the jaws of the vice grips with electrical tape.

Yeah, where I marred it, it is slight and almost disappears under the bolt catch. A bit annoying, but probably only noticeable to me and now I know where the tape is needed--everywhere that gets near a tool. I know this of course, I just get impatient when round pegs aren't going in round holes, so to speak. Maybe I'll just tape up the vice grips like you suggest next time and save a some time.

[Gi14]

I felt the exact same way after I did mine. I had done a bunch of pistol work before I'd ever even held a rifle. I had an wrong-minded assumption that the rifle would be harder to work on because it was exotic to me. In the end I think it was much easier to assemble the AR lower than something like a Beretta 92/96 top to bottom.

Grats on doing it yourself!

I just had my lower apart last night to see what the first 500 rounds did to the contact surfaces...not much.

[electronics]

I felt the exact same way after I did mine. I had done a bunch of pistol work before I'd ever even held a rifle. I had an wrong-minded assumption that the rifle would be harder to work on because it was exotic to me. In the end I think it was much easier to assemble the AR lower than something like a Beretta 92/96 top to bottom.

Grats on doing it yourself!

I just had my lower apart last night to see what the first 500 rounds did to the contact surfaces...not much.

I was actually going to get help from the local guy who I buy most of my stuff from, but to my surprise he had never assembled a lower either. I already have a decent amount of tools and punches and things so I figured heck with it, going to need to learn how to do this eventually. I've never done any pistol work except on Glocks which was quite simple.

I know one thing, now that I've assembled it from parts it'll be a lot easier to diagnose any problems I might run into in the future.

[mojo]

IMO, assembling an upper is easier than assembling a lower.

Only if you have a receiver block , vice, and some good wrenches.

Lower = punch, tape, hammer, *razor blade

* razor blade helps with front take down pin but is not required.