Help putting together an AR lower

Preparedness Depot in Acworth, GA

AtlMedic

Not A Doctor
Mar 25, 2015
2,644
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Smyrna, GA
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30082
so I should be picking up an AR lower this week. I have a LPK I am going to get the few pins I need and the stock stuff.

The problem is I've never done it and was wondering if anyone would want to help me assemble it?

I live in Smyrna and I will bring beer.
 

dougiemac

Lord of Chaos
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Lifetime Supporter
Aug 26, 2014
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so I should be picking up an AR lower this week. I have a LPK I am going to get the few pins I need and the stock stuff.

The problem is I've never done it and was wondering if anyone would want to help me assemble it?

I live in Smyrna and I will bring beer.

I've not done one either... but Youtube is your friend. :)
 

AtlMedic

Not A Doctor
Mar 25, 2015
2,644
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Smyrna, GA
Zip code
30082
I've watched the YouTube videos and could probably make it happen. But if someone who's done it wants to help/supervise I wouldn't say no. Plus having a beer with a bother member is always fun.

Maybe you could come too @dougiemac
 

Laces_Out_Marino

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Aug 14, 2015
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I have built 1 lower using youtube and one using a video from full30.com. Im no expert but if you want help I'm always down for a beer
 

becausefu

Woodsman
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Mar 25, 2015
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Three little tricks.

The rear take down spring hole ..... tap it with a 4/40 tap and use a set screw to hold it in place, clip about 4 coils off the spring before using it.

Second trick, front take town pin ....put the spring in the hole and use a punch to compress the spring, take a needle and stick it in the hole in the side to keep the spring compressed when you remove the needle. Drop the detent into the hole, slide the pivot pin in .... pull needle.

Third trick is on the bolt catch pin .....take a file or a dremel tool to put a point on the roll pin so it starts MUCH easier.

The bolt catch pin is where 9 out of 10 scratches come from.
 
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fyroc

Developer
Mar 25, 2015
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Philadelphia
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Three little tricks.

The rear take down spring hole ..... tap it with a 4/40 tap and use a set screw to hold it in place, clip about 4 coils off the spring before using it.

Second trick, front take town pin ....put the spring in the hole and use a punch to compress the spring, take a needle and stick it in the hole in the side to keep the spring compressed when you remove the needle. Drop the detent into the hole, slide the pivot pin in .... pull needle.

Third trick is on the bolt catch pin .....take a file or a dremel tool to put a point on the roll pin so it starts MUCH easier.

The bolt catch pin is where 9 out of 10 scratches come from.

Nah. Take a pair of pump pliers for the bolt catch pin. Wrap some masking/duct tape around each end to prevent scratching. There is no tapping or anything, you just squeeze the pin in place and you're done with it.

For the pivot pin, this will make life a lot easier for you.
http://www.midwayusa.com/product/91...nt-and-roll-pin-installation-tool-ar-15-steel

I wouldnt tap anything. If youre worried about scratching anything this will fix it
http://www.brownells.com/gunsmith-t...ckening-browning/aluminum-black-prod4941.aspx

I've lost count of how many lowers I put together. I have 4 stripped sitting in my closet right now.
 

becausefu

Woodsman
Trusted Trader
Mar 25, 2015
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Not everyone has a set of knipex pliers.

Aero Precision taps the hole from the factory ....makes it easier putting on the receiver end plate, or when putting on an A2 stock you don't have to worry about the spring sticking out.

Why buy a special tool to do something when you probably have everything else just sitting around.

I've put together plenty of lowers. Those three little tricks will help
 

AtlMedic

Not A Doctor
Mar 25, 2015
2,644
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Smyrna, GA
Zip code
30082
Thanks guys. I do think a M&G for the experienced guys to help us less experienced ones could be fun. I bet even some of the guys who have built a bunch may learn a new trick or two.
 

Buckeye76

Frontiersman
Mar 27, 2015
254
144
63
Georgia
Not everyone has a set of knipex pliers.

Aero Precision taps the hole from the factory ....makes it easier putting on the receiver end plate, or when putting on an A2 stock you don't have to worry about the spring sticking out.

Why buy a special tool to do something when you probably have everything else just sitting around.

I've put together plenty of lowers. Those three little tricks will help

I really like the aero lowers.

OP, a pair of vice grips with the jaws wrapped in electrical tape and some painters tape to put around the holes will be a big help.
 

Green Panther

Frontiersman
Mar 25, 2015
291
139
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Smyrna, Georgia
so I should be picking up an AR lower this week. I have a LPK I am going to get the few pins I need and the stock stuff.

The problem is I've never done it and was wondering if anyone would want to help me assemble it?

I live in Smyrna and I will bring beer.
You live close by. Bring it over and we can get it done in a few minutes time.
 

Wallace

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Mar 26, 2015
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OP, I have all the proper tools to assemble it. If you ever want to come by Euharlee, I can assemble it and show you how to do it right. I have quite a few lowers laying around, so we can take them apart and re-assemble if you want more practice.

Let me know.
 
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Wallace

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Mar 26, 2015
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Three little tricks.

The rear take down spring hole ..... tap it with a 4/40 tap and use a set screw to hold it in place, clip about 4 coils off the spring before using it.

Second trick, front take town pin ....put the spring in the hole and use a punch to compress the spring, take a needle and stick it in the hole in the side to keep the spring compressed when you remove the needle. Drop the detent into the hole, slide the pivot pin in .... pull needle.

Third trick is on the bolt catch pin .....take a file or a dremel tool to put a point on the roll pin so it starts MUCH easier.

The bolt catch pin is where 9 out of 10 scratches come from.
1) Not a fan of tapping detent spring hole. The spring goes in fine as long as you are paying attention on install and remember its in there if your taking the end plate off.

2) The detent spring in the front can be easily installed with a 1/4 clevis pin and punch. After you do a few, just using some lithium grease on the spring will hold the detent vertical, at that point you just get use to using your fingers on the side of the detent and press down and into the receiver with the pin. Goes in quickly and without extra tools.

3) Do not dremel your roll pin. KAK and Crosstec both make an extended roll pin starter punch. Just use painters tape to protect the lower from the punch and hammer when driving in the pin. Crosstac also make the receiver blocks the will hold the receiver vertical making install a breeze. The other option is the cheap Wheeler armorers block that help holds the lower vertical for roll pin install. You can start the pin by "slightly" squeezing one end with needle nose if it just doesnt want to start. Then finish driving it in with roll pin punches (something like the punches Grace USA make - ball end to keep the punch centered on the roll pin).

OP, also, never dry fire an AR lower off of the upper. It can/will brake the bolt catch and/or damage the receiver.
 
Last edited:

Laces_Out_Marino

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Do yourself a favor and grab this if you don't have punched yet. It has everything you need. I grabbed one with the BCM LPK and it made my second build a ton easier, you get the punches and the biggest help is the roll pin starter punches.
 

Wallace

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Forgot to mention, I have Aeroshell 33ms and automatic center punches for properly installing the castle nut and staking it.

Be sure to support the trigger guard tabs on the receiver while installing the guard.. If not, you can relatively easily break off one of the ears of thee receiver. Not hard to do, again, the Wheeler armorer block helps with this too.

FCG installs with ease using the Geissele trigger fitting pin ($15 tool). The end is beveled/chamfered so it makes lining up the disconnect super easy for the pin to drift in. You can do the same thing without tools or by using a regular drift punch, but the Geissele tool is one of those nice to have things laying around. Just dont forgot to double check that your hammer spring is installed correctly and not backwards.

Last tip from me. If your grip comes with a flat head screw vs a socked head cap screw like Magpul provides, put painter/masking tape on the correct size flat head to help install the screw. If not, you will end up trying to drop in the screw with needle nose (which can get annoying). The tape on the screw driver head will hold the screw and allow you to easily get it started without risk of cross threading. If you do cross thread though, a 1/4-28 tap can repair the threads (I have one if you need it).
 

Laces_Out_Marino

Tracker
Trusted Trader
Aug 14, 2015
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1) Not a fan of tapping detent spring hole. The spring goes in fine as long as you are paying attention on install and remember its in there if your taking the end plate off.

2) The detent spring in the front can be easily installed with a 1/4 clevis pin and punch. After you do a few, just using some lithium grease on the spring will hold the detent vertical, at that point you just get use to using your finger on the side of the detent and press down and into the receiver with the pin. Goes in quickly and without extra tools.

3) Do not dremel your roll pin. KAK and Crosstec both make an extended roll pin starter punch. Just use painters tape to protect the lower from the punch and hammer when driving in the pin. Crosstac also make the receiver blocks the will hold the receiver vertical making install a breeze. The other option is the cheap Wheeler armorers block that help holds the lower vertical for roll pin install. You can start the pin by "slightly" squeezing one end with needle nose if it just doesnt want to start. The finish driving it in with roll pin punches (somehting like the punches Grace USA make - ball end to keep the punch centered on the roll pin).

OP, also, never dry fire an AR lower off of the upper. It can/will brake the bolt catch and/or damage the receiver.

I found if you don't have a vise block you can use a metal mag and wrap it in some electrical tape for a snug fit if it is loose