I have a couple of lowers and complete kits to build them, but I'd like the ultimate instruction to do it right with no parts going missing.

Anyone help? Thanks.

This step-by-step tutorial is even better than a video, as you don't have to constantly hit play/rewind/etc:

https://www.ar15.com/guides/fi...r/index.html?gid=183


There's a front pivot pin install tool (as shown in the above tutorial), but buying that specialized tool is not 100% necessary. If you don't have that tool, you can use a 3/16 hex wrench to hold the pin and compressed spring in place during install, as shown here: https://www.itstactical.com/wa...ot-pin-installation/

And when installing this front pivot pin, do so inside of a large clear 1 or 2 gallon ziploc bag. If you've never done it before, it's easy to slip and launch the tiny detent and spring across the room, never to be seen again. Doing it inside a bag keeps these parts contained if/when they go *sproing*.

Thanks, RogueJSK, I appreciate that!

I like to use a straight razor or similar thin, flat metal object for that particular detent.

quote:

Originally posted by Oat_Action_Man:
I like to use a straight razor or similar thin, flat metal object for that particular detent.

Yep, I use an Exacto knife with a wide, flat chisel blade to compress the detent. But I still find using the intermediate hex wrench to be easier and less error-prone than simply going straight to the detent pin.

Brownells has a full series of videos that are very good IMO.

Thanks for the additional info, guys.

Buy this for the front pivot pin installation...

1/4 in. Clevis Pin

I always thought this video was pretty good.

https://www.youtube.com/watch?v=du3GtxNiBac

Brownells is also good. I installed a new trigger in my ar in like 10 minutes.

quote:

Originally posted by mr228:
Brownells is also good. I installed a new trigger in my ar in like 10 minutes.

On that note, having a slave pin to hold the trigger assembly together while you sit it in the receiver is a real plus.

I assume you can buy them, but the one I use came with a trigger I got (maybe an ALG?).

Be sure to support the bottom of the trigger guard "ears" before you drive in the trigger guard roll pin to reduce the risk of cracking one off.

quote:

Originally posted by bozman:
Buy this for the front pivot pin installation...

1/4 in. Clevis Pin

That's what I use. Available at any hardware store for around a $1. Can't beat that!!

A flashlight is the tool I highly recommend when it comes to assembling the lower. Seriously kick it on high and you'll find your pins and springs when they go plaid out of your receiver.

There is a tool that looks like a hex key/allen wrench but its round and has a hole in the long end that works great for the front takedown pin spring and detent. Basically looks like a bent Clevis pin with only one hole, I strongly recommend it.

The biggest issue I had with assembling a lower was installing the bolt hold open pin. Rogue gave the best site to use. I have used it many times over the years.

quote:

Originally posted by patw:
The biggest issue I had with assembling a lower was installing the bolt hold open pin.

Yep. That and the trigger guard pin turned my ~15 min assembly into over an hour. That's when I decided to just buy complete lowers from now on Not worth the aggravation and flattened pin heads