"Know your AR-15" challenge: Answers now posted

[Mack]

Here are two builds I just completed. Compare each to a standard mil-spec A2 lower and list the specific differences.
No prize -- this is just for fun. I'll post the answers in a few days.

"Build 1"

"Build 2"

 

[CooperS7777]

The top one looks like a composite reciever, and the backstrap on the lower one looks a bit off, but again its a bit hard to tell on my Black Berry!

 

[Cross-X]

JP Rifles fire control trigger system, chromed or brushed mag release and safe-fire selector, and Apex stock.

 

[01SVTvert]

Top: rear sling swivel,

Bottom, changed hammer (no idea what kind), ergo grip, Stock, sully? triggerguard, mag latch, bolt release and selector brushed / plated? also appear to be anti rotation pins

 

[lord1234]

something hinky going on with the pistol grip on the bottom one.

 

[FhvnLT4A]

The grip on that bottom one looks like a Magpul MIAD.
The Trigger Guard is also magpul i think...
Sear pins are different, as is trigger group and pin.
Are the bolt catch, mag release, and seletor polished metal????
On the top one, all i see are the sling swivel stud, and not sure what else

 

[Mack]

Answers for Build 1

With Build 1, I was going for light and compact.

The ONLY thing A2 mil-spec about Build 1 is the "lower parts kit" (pins, detents, springs, hammer, trigger, disconnector, bolt stop, mag release, safety selector and pistol grip).

The Vulcan Armament receiver is made of carbon fiber/aramid (I was impressed that CooperS7777 recognized that the receiver was "composite" on his Blackberry!). Aramid is an organic polymer http://en.wikipedia.org/wiki/Aramid and receivers made of Aramid are half the weight and twice the tensile strength of aluminum.

The buttstock is A1 mil-spec, NOT A2 mil-spec. A1 buttstocks are 5/8 inch shorter than A2 and therefore don't require the buffer tube spacer to install. There are some other differences you can see: the sling swivel is mobile on the A1 compared with the A2 -- the A2 doesn't "swivel" at all but is fixed in the stock.

A2 has the buttplate trapdoor and storage compartment; A1 doesn't. The A1 buttplate is more rounded and pliable = more comfortable to shoot.

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I'll post the Answers for Build 2 tomorrow.
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[CooperS7777]

Sweet! I zoomed in on it quite a bit, but the thing that really gave it away for me was the metal serial number inlay on the mag well.

 

[Mack]

Answers for Build 2

If you think of Build 1 as a BUICK (with some exotic and used parts), Build 2 is a CADILLAC (with some luxury options).

Everyone got the most obvious features, namely, the chromed/brushed/polished controls and the skeleton stock.
Cross-X and 01SVTvert both recognized some differences in the fire control group. 01SVTvert and FhvnLT4A noticed that
there was something different about the hammer and trigger pins (very good!). FhvnLT4A also pointed out the Magpul
pistol grip and trigger guard.

Here's the complete list of features:

0. Mil-spec lower receiver from Charles Daly Defense
http://www.charlesdalydefense.com/lowers.asp

1. Ace Buttstock. (The foam overtube makes for a much better, more comfortable cheek weld for use with a scope.)
http://riflestocks.com/catalog/product_info.php?cPath=75_77&products_id=189

2. Magpul Enhanced trigger guard
http://www.magpul.com/catalog/index...id=236&zenid=378506cce7647247a684ec46aa625222

3. Magpul MOE pistol grip. (The MIAD "Mission Adaptable" version has too many parts to lose.)
http://www.magpul.com/catalog/index.php?main_page=product_info&cPath=78_125&products_id=286

4. Chrome mag release, bolt catch and safety selector made by DPMS. (What's a classic luxury car without some chrome?)
http://www.midwayusa.com/viewproduct/?productnumber=146995

4. Chip McCormick super match trigger with "anti-walk" hammer and trigger pins
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=20732&title=AR-15 SUPER MATCH TRIGGER

5. (not visible) Enidine Ar-Restor hydraulic recoil buffer
http://www.brownells.com/aspx/NS/Store/ProductDetail.aspx?p=22351

 

[WeedWhacker]

Is the foam tube rigid? Or is it flexible?

1. Ace Buttstock. (The foam overtube makes for a much better, more comfortable cheek weld for use with a scope.

 

[Cross-X]

Mack, do you really need a hydraulic shock absorber for a little old .223?

 

[Stef]

Nice. I just ordered one of the ACE buttstocks for my AR build. Does that Enidine recoil buffer make much of a difference?

 

[FalArAk]

Mack, do you really need a hydraulic shock absorber for a little old .223?

Many people have been permanently disfigured due to the high recoil of the .223 platform.I broke my nose and dislocated my shoulder last year while shooting offhand.

 

[Mack]

Is the foam tube rigid? Or is it flexible?

Flexible. It's a bit of a challenge to slide over the buffer tube.

 

[Mack]

Nice. I just ordered one of the ACE buttstocks for my AR build. Does that Enidine recoil buffer make much of a difference?

It's been way too cold and snowy to get to the range, but I'll do a range report in due course.

 

[Mack]

Mack, do you really need a hydraulic shock absorber for a little old .223?

Probably not, but I'll let you know when I finally get to the range.
Actually, there was another reason I bought it -- regular buffers were back-ordered at all the places where I usually get my parts but the AR-restors were in stock.