Okay,

I have been reading on this forum and other sources about the variants of the A2.  And all I can say is WOW......there is so much and so much to absorb of the various differences along the development and evolution.  

I have been thinking of and gathering parts for.....a couple of builds.  I want to build a standard M16A2 rifle clone and perhaps a carbine using an A2 upper.

The questions I have been trying to determine is what sort or style of lower receiver should I use to build on?  Is there a particular brand of lower I should seek or as I have read there were some A1 style lowers used.  So perhaps a retro lower from NDS would work?

Just wondering what most people use in the way of lowers to build their M16A2 rifle on?  

Also, is there a website out there that documents the various weapons using the A2 upper?  Like retroblackrifle.com is for the A1's?

Thanks
S

There's no "Retro Black Rifle"-esque resource that I know of that very accurately documents the A2 series quite the way RBR does.  

You can find tidbits all over, though - the "Show me some 727s" thread may help to answer some of your questions about lowers - as will some of the stickied threads about USGI M16A2 variant parts.  

A lot of USAF and USA M16A2s were also earlier models that had been converted to A2 specs, and therefore have A1 or earlier lowers that have been re-marked as A2s.  For the most part, the USMC purchased complete weapons from Colt first, then FNMI.  

~Augee

LMT has a very nice A2 lower.  Delton has a decent one that is available for cheap money.

Almost all of the basic, forged lowers out there are of the correct shape for a "proper" A2 build.

Consult this thread to see the major differences between the A1 and A2 style lowers http://www.ar15.com/forums/t_3_123/575112_A1_A2_Lower_Differences.html

Thank you, I have been reading and this forum is just full of information and experience.
Besides a normal looking M16A2 rifle with a black finish..........I think I might build a 727 as well.
I have a nice A2 upper with a grey finish........so I sort of thought about maybe building an early style A2 ?

Thanks

@ Tyrantresister and Curcuits

Thanks for the suggestions.  I was wondering what subtle differences there might be between the different A2 lowers on the market.  
I will check with those sources when its time to get one.

Thanks

http://www.nodakspud.com/newstuff.htm

In terms of A2 lowers you will find three areas of possible variance.  

1. The stock itself

2. The quality of the lower parts kit

3. The material of the receiver extension


The lowers themselves will be all pretty much the same, aside from the fact that some lowers have tighter magwells than others (which I can't stand as then not all mag types will drop free).

The A2 stocks that are out there are made of all different types of polymer materials, and are not all formulated to the same A2 mil spec.  The strongest material will be that made with the mil spec nylon impregnated zytel.

99% of the rifle receiver extensions out there are made from 6061 aluminum which is not as strong as the mil spec 7075.  Even BCM and LMT use 6061 aluminum for their extensions.  7075 is stronger and less prone to breakage if you ever were to use your rifle in a hard use combat situation, bayonet drills, etc.  If that part breaks the entire rifle fails, so it is very important to have that part as durable as possible.  

Only Colt and specialized armament offer rifle extensions in 7075.  Colt only offers theirs with the complete rifle.  You can buy the 7075 extension from specialized armament but it costs twice as much as the 6061 extensions (which they also sell).

http://www.specializedarmament.com/products/Receiver_Extension_Rifle_Forged-135-291.html

Wow,

Thanks for the information Guys!

How would I tell if a stock is made of mil spec nylon impregnated zytel?

Is there a color of pattern difference?

44Echo10 beat me to it! Keep an eye on these guys. I have one of their A1 uppers and it is good quality.

I recently completed 2 A2's using Spikes lowers. Support the LGS @ $70 bux each. My FN M16 upper went right on with no issues. Consecutive serial #'s no less!
The other A2 was a "modern" version with a new FN 18" rifle length gas barrel and a Daniel Defense 12" light rail. The "modern" A2 grew from a single FN upper.

Anyway, hang on to your wallet! A2's can get expensive!
chris

Pics of modern A2?  How do you find the recoil and cycling of the 18" rifle gas with various .223 ammo types?

This is what I was going to say. Buy Colt/FN if you want it to be 110 % clone, but in my opinion when building a clone the brand of lower doesnt even matter. 90 percent of forged lowers are the same damn thing

Hi Blain, your A2 posts are what has inspired me to build the A2's that I have. I don't have any pix yet but plan to feature all 3 of my A2's here. I also have a Dissy that I re-arranged from a DPMS Sweet 16. I turned down the bull barrel and added the front sight hardware and gas block.
My "modern" A2 is an FN upper with a noveske BCG I got both here at the EE. The DD Light 12 rail (also used) fills the space from the carry handle to the front sight nicely. This is the barrel I used. So far the only shooting I have done has been with Remington UMC cheapo ammo and some bulk remanufactured .223. Prob 200 rounds so far and no malfunctions of any kind using Magpul 30 round and "correct" Colt GI 20 rounders. The gun shoots "soft" similar to my 20" M16 top end. haven't done a cold weather test as you did. Even though my eyes are over 60 years old, I still like Iron sights!
chris

All of the BCM-branded receiver extensions for sale on their web site right now are advertised as 7075T6.

Did you specify color and i missed it? Cause what i did... Is use nodak spud gray a2 lowers. You pay more, but the receivers are awesome... And if you want a gray finish, well they are the game in town. They also leave plenty of room if youre wanting to custom engrave it with a reproduction rollmark....

Carbine receiver extensions are not the same as rifle receiver extensions, brother.

The rifle receiver extension currently being sold as a stand-alone part on their site isn't advertised as "BCM".

The specs on complete BCM rifles with A2 stocks read "BCM® Milspec 7075-T6 Receiver Extension"...

http://www.bravocompanymfg.com/specification/bcm_sam_rifle.php

http://www.bravocompanymfg.com/specification/bcm_mk12_mod0.php

I wouldn't trust that as being accurate, unless you think you can fire a carbine buffer in a rifle extension  

I don't know - maybe you can.  The other way around might be more of a problem because of the length of the buffer.  I have two rifle gas system uppers on lowers using carbine buffers without any issue, although one has a carbine extension and the other has a UBR with its proprietary extension.  The point being a rifle buffer is heavier than any carbine buffer except an H3, but the weight of the rifle buffer obviously isn't driven by the gas system or my rifles would be unreliable.

You certainly couldn't put an A2 stock on a carbine receiver extension.

.....thanks man!  It's always nice to hear if I helped inspire or motivate someone else to take similar action in terms of equipment.  I've always been a fan of KISS, old school iron sights, and the classic look of the original M16 type rifles.  Not to mention, ARs are most durable and reliable in their stock configurations (for you SHTF types)!    

I saw your A2s on the other thread that you posted, very nice work there.  I recommend that for your next project you try a 20" lightweight barrel A2, or an 18" rifle gas A2 upper.  I think you'll really appreciate the weight and handling even more so than the stock A2.    

18" A2 Goodness!



Pencil Barrel A2!

When building a proper 727, you will need an A1 lower (NDS). The 727 is sort of a transitional carbine as was the 723s. They were usually on A1 lowers (SAFE, SEMI, AUTO) as opposed to the A2 lowers (SAFE SEMI, BURST). You will want a 14.5" 5.56 NATO 1/7 CL M4 profile barrel (w/ standard non- "F" marked FSB) and permanently attach an ext. A2 FH to make it non-NFA. You will want to source a set of CAR 6-hole handguards, fiberlite stock, 2-position buffer tube (NDS), an early castle nut, Delta ring assembly, and standard CAR buffer.





I would suggest ordering a NDS-16A1 lower from NDS now if you have not done so already. It can take upwards to nine months sometimes. Believe me, I know. Check with boywonder777 in the retro forum for handguards and maybe even the barrel. Model 1 Sales has a fiberlite stock that works perfectly, unless you prefer on finding the real deal and then you will pay dearly. NDS has the 2-pos. buffer tube and they usually have some in stock as well as charging handles in XM Grey. If the upper you are using is black, you can use a standard black CH. Good luck with the build.

727's were on A2 lowers with S-S-A fire control groups as well. I've seen them both ways.   Biggest purchasers/users were the Squeals:




A good lower for a 727 would be a McKay RM16A2 with SAFE-SEMI markings, or a Colt Government receiver set.  We actually referred to these as M16A2 carbines back in the day before the M4 came about.