Lightweight AR15 Build - CAV-15 MKII Lower & Pencil Barrel

This build started a year or two ago with the purchase of a GWACS Armory CAV-15 MK II one-piece lower/stock.
I wanted a carbine that was light enough for my wife to shoot as she has physical limitations that make shouldering an average rifle too difficult for her to enjoy shooting. By using the polymer lower (it's made of Dupont Nylon 6) you can shave a full pound off compared to a complete standard lower with stock. Couple that with a lightweight pencil barrel, and I think I can get the weight down to where she can handle it.

I'll add a full parts list at some point, but at the time of this posting I have the following:

CAV-15 lower/stock
Anderson Sport upper (no forward assist/no dust cover)
Tom's Tactical LPK with upgraded Nickel Teflon trigger group
Charging handle
Magpul front/rear BUIS
Faxon 16" mid length pencil barrel

I still need:
Muzzle device
Bolt carrier group
Buffer/spring (I have a standard buffer/spring, but may get a lightweight setup)
Hand guard
Adjustable gas block
Gas tube

This should be interesting. I can't wait to see what this totals out at. I'm trying to make it as light as I can, but there's no way I can afford some of the crazy-light parts that are available on the market, so I'm not trying to compete with $3,000 lightweight guns - I just need it to be "light enough" for my wife.


If anyone has any tips, I'm all ears! If anyone has any questions, I'll answer as best I can.

I never knew a carbine could be so light. My first AR (before I had an understanding of barrel profiles) came with an HBAR, so this thing feels unbelievably light (even assuming it will weigh more once completed) and feels more like a toy.

I just got the barrel yesterday so I slipped it onto the upper/lower to get a better feel for it. Now that it's starting to look like a rifle I want to keep going and finish it, but I have to buy as I can afford the parts.
I'll post up some pics in a sec...

Here's the heart and soul of a lightweight build - the barrel.
I don't think there's one other part where you can shave more weight than on the barrel.

I went with the highly regarded Faxon 16" pencil barrel. There are others out there, but this seems to be the lightest - without needing to take out a loan.
I picked it up from Faxon directly for $140 (20% off sale) and was $148 shipped.

http://i886.photobucket.com/albums/a...pshjtf0tla.jpg

http://i886.photobucket.com/albums/a...pshi8zmtwb.jpg

http://i886.photobucket.com/albums/a...psax1abwht.jpg

http://i886.photobucket.com/albums/a...ps40dshbhk.jpg

http://i886.photobucket.com/albums/a...pspadrbxqx.jpg

Some comparison shots - it's hard to believe how thin this barrel is without seeing/holding it in person!

(birdcage is just on there to protect the threads and to get an idea of how it will look with a muzzle device)
http://i886.photobucket.com/albums/a...psyafrpek8.jpg

http://i886.photobucket.com/albums/a...pswktnqge6.jpg


I should have taken the handguards off the other rifle for a true comparison, but most of you know what they look like.

http://i886.photobucket.com/albums/a...psdms10xdz.jpg

http://i886.photobucket.com/albums/a...psthrrsku6.jpg


There's the GWACS Armory CAV-15 MKII polymer lower. I will comment more on that later, but if you have questions about them, just ask - it's a pretty neat lower and super light and durable - pretty much universally accepted as the best choice out there as far as polymer goes.

http://i886.photobucket.com/albums/a...pskjdoglc0.jpg

I had started a thread in the Rifle subforum asking about lightweight bolt carrier groups and how they may affect recoil.

I was considering the AIM lightweight as it's on sale for $89 and I can't justify spending the crazy amounts that other companies want for lightweight BCGs.

I'm not 100% sold on needing a lightweight BCG and started looking at "standard" bolt carrier groups.
My default would be to just get an $89 PSA premium BCG - I have one in another carbine and I've seen mostly positive reviews.
Some other "good" brands start getting crazy with pricing and I would like to stick near $100 if possible.

I see that Primary Arms has the FailZero EXO coated M16 cut BCG on sale for $99.99
I'm not a BCG fanboy so I don't eat sleep and breathe BCG technical details and I get confused by the various "coatings" and what the purposes are for each of them.

A quick search suggests this is a pretty decent product. I have to wonder if this would be a good move to buy this as opposed to the PSA BCG if I decide not to go with a lightweight. The price sure seems right.

Any thoughts?
Any other suggestions for a quality BCG that doesn't break the bank?

I have a Fail Zero in one of my builds. It has been fine so far, I don't have a ton of rounds thru it, probably 500-750. Cleans up nice. I got mine from PA for $100 also.

Quote:

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Originally Posted by chkrdflg

I have a Fail Zero in one of my builds. It has been fine so far, I don't have a ton of rounds thru it, probably 500-750. Cleans up nice. I got mine from PA for $100 also.

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Thanks for the input.
I tend to over think things, but when you don't have money to "waste", you want to be sure you're making the right decisions and not end up having to "buy twice".

I haven't nailed down what BCG I want and the Fail Safe is no longer on sale.
I'm looking hard at the Right to Bear brand lightweight BCG for $105 but it's out of stock at the moment.
https://cdn3.volusion.com/jreda.hxva...jpg?1491211872

I ordered a gas block instead.
I'm getting the SLR Rifleworks (not the titanium) Sentry 6 from Righttobear.com
I looked all over and the current sale coupled with free gas tube (I needed) and additional discount is the best price I can find.
It came to $117.40 including the gas tube and shipping.

http://ep.yimg.com/ay/yhst-137019325...ck-0-875-1.gif

I've always heard that polymer lowers are inferior to aluminum but I've been intrigued with the idea because I want to get an 80% and mill it out. Without a drill press, I've been looking at polymer 80%s with jigs that you can complete with just a cordless drill and router.

Anyone tried one of them or have doubts that one could hold up?

Quote:

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Originally Posted by alpacaheat

I've always heard that polymer lowers are inferior to aluminum but I've been intrigued with the idea because I want to get an 80% and mill it out. Without a drill press, I've been looking at polymer 80%s with jigs that you can complete with just a cordless drill and router.

Anyone tried one of them or have doubts that one could hold up?

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These CAV-15 lowers are unlike the common polymer lowers on the market. For one, the known weak spot on typical polymer lowers is where the buffer tube threads into the lower. They are known to crack at that weak point and some companies now put metal thread inserts there to strengthen it.
The CAV-15 lower is stronger due to the one-piece design.

I have a New Frontier poly lower that i used for a 22 build and it seems to be made of an entirely different polymer - more "plasicky". I don't care for it and won't buy another.

These CAV-15 lowers have pretty universally good reviews as far as durability goes.

Here - I posted this info in my 7.62x39 build thread...

Since this tread may gain views from those interested in the GWACS Armory CAV-15 lower (formerly Cavalry Arms CAV-15) I'm going to post links to articles, reviews, videos, and how-to/maintenance info in this post and add to/update as I find them.

http://cdn2.bigcommerce.com/server90...g?t=1366745867

From the company website:

GWACS Armory, is now located in Jenks Oklahoma, is a 07 FFL manufacturer of firearms focused on quality product and a high level of service. Our products are made in the USA. We support the second amendment. Many of our employees are veterans. GWACS Armory is also a 08 FFL importer of firearms. Our flagship product is the CAV-15 MKII AR15 lower receiver.

GWACS Armory is registered with SAM. CAGE CODE: 6KRL2
CAV-15 MKII Receiver Features:

GWACS Armory, LLC, produces and sells the CAV-15 MKII, a versatile, lightweight, durable rifle that resists corrosion and impact better than traditional aluminum based AR15-type weapons.

We offer a life time warranty on our CAV-15 MKII and will also honor the warranty of the CAV-15 MKII offered by Cavalry Arms. Contact our staff for further details.

Choice of colors.

Receiver weight (complete) is almost a full pound lighter than a many complete aluminum receiver with an A2 stock.

A1 Length Integral Stock (5/8" shorter than A2) with sling loop. 13" Length of Pull.

Uses standard AR15/M16 magazines. The wider magazine well accepts submachine gun magazines in pistol calibers. With caliber conversion upper receivers and magazine blocks.

Uses all standard mil-spec parts with the exception of the take down pins. The front pivot and rear pins are a Quick Take Down style with Detents built into them. This allows for quick and easy removal of the pins while maintaining a positive lock.

Longer life, Nylon6 resists impacts and wear better than aluminum.


Links pertaining to the GWACS Armory CAV-15 MKII:

History of the cavalry Arms CAV-15 (good read!)

VIDEO - Abuse test

Technical - Triggers - what works and what doesn't

Review - Detailed review (2012)

Customizing - Article about custom mods that can improve upon the base product

Technical - Video tutorial showing complete installation of lower parts kit!


Torture test video (full version)...

https://www.youtube.com/watch?v=xjhvi8c0MF4