Lightening the AR-15


Badger Arms
May 19, 2003, 11:48 PM
I wanted to field this question. What ways are there to practically lighten the AR-15? I know that one of the most common ways is to turn the barrel smaller, down to about .600" is about as small as I've seen it. Are there any other ways to help the weight situation? It's not that the gun is overly heavy, but the .223 doesn't kick that much either. I want my kids to be able to transport it themselves along with the ammo, earmuffs, targets, and shooting glasses. I believe they will feel better about transporting them themselves. These kids are NOT recoil shy, so that is not a factor. Please help me out?

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May 19, 2003, 11:54 PM
I've been wanting to build up a lightweight AR for my wife. The old Colt SP1 would be ideal, but we don't want to pay pre-ban prices.

If you're willing to go with the older skinny barrel and shoot 55 gr ammo, there's a lot of weight savings right there. Add a A1 butstock and ditch the carry handle for a flat top receiver (especially if you're using optics) and you'll save some more weight. If you really want to dump every ounce, try a shorter barrel or even use an flat side upper without a forward assist. Of course, with those you'd still have the carry handle, but if you wanted to keep the handle anyway it would be lighter.

May 20, 2003, 01:23 AM
Go to

Kurt does excellent work, fair prices, reasonable turn times.

Jeff White
May 20, 2003, 01:31 AM
Some of the fake collapsible stocks are lighter then even the A1 stock. You could try to find an M16 upper (no forward assist).

Have you looked at the MDAR15shooters site? I think Forest had some articles there on building super lightweight ARs.


Badger Arms
May 20, 2003, 02:12 AM
Jeff, do you have a link? I've been on that site for 10 minutes now and can't find the darn thing.

Jeff White
May 20, 2003, 02:23 AM
No, I don't have a direct link. I'll e-mail Forest. It was also the subject of a few threads on the AR15 mailing list.

Go to AR15-L@yahoogroups you should be able to pull it out of the archives. Some of the guys got pretty creative. I think there was one or two down at around 4 pounds.


May 20, 2003, 07:17 AM
And don't forget Bushmaster's Superlight with the Stubby/"Entry" stock. Under 6 pounds unloaded.

I've got a Bushmaster Superlight barrel on my current A3 AR, comes in around 7 pounds.[

May 21, 2003, 09:21 AM
Those "Entry Tactical" or "Stubby" stocks are AWEFUL short (10.5" LOP) and adding anything to make it longer and more comfortable is gonna add weight too.

The ACE Boom Tube stocks are lighter than any of the AR stocks I personally know of, and they are available in A2, A1, and custom LOP's.

May 21, 2003, 09:42 AM
How about fluting the lightweight barrel? Might shave off a few more ounces.

My Bushie carbine has a Surefire M500A weaponlight that makes the gun noticeably barrel-heavy. Fortunately my (heavy) barrel is fluted so it saved a bit of weight.


May 21, 2003, 10:00 AM
The beauty of the AR15 has been lost in all the bloat, hasn't it? The lean and mean Colt SP1 was the ticket for you. It's my favorite type of AR15. Pray for the AW to end so you can buy an original! :o

May 21, 2003, 11:02 AM
Sure, get one of the Bushmaster made Corbon 16s.

On the Bushy website they advertise a rifle under 4 pounds!

But then that doesn't solve your currect dilemna. You might think of trying one of the Cavarms lowers and mate it with an ultralight barreled upper.

Good Shooting

Badger Arms
May 21, 2003, 12:35 PM
So far the options aren't looking so good. I've talked to a few around here and got shown a picture of the OlyArms 'Swiss Cheese' gun and their 'noodle barrel' featherweight. My concern is that these barrels will heat up faster and be less accurate. I've already got a DPMS featherweight barrel and that is about as light as I'm willing to go. I don't think it's safe to flute it. The other concern is that I don't want a CAVarms lower. I've looked at their crap and just want to stay away from that. Plus, the stock on the CavArms is LONGER than an A2 stock!!! What the 'offline' concensus was was this... the parts that need to be looked at OTHER than the barrel are:

Front Sight (steel... do they make an aluminum one?)
Upper Receiver (need A-1)
M-4 Stock pinned in place (so I can pin it short enough for my Daughters)

The things I was thinking of as possibly saving weight were:

Removing the weights from the buffer (is this adviseable?)
Milling the Bolt Carrier to lighten it
Drilling holes in the lower that are hidden by the grip, stocks.
Replacing the handguards, barrel nut, delta-ring/spring assembly with Armalite fiberglass handguards.
Naturally I'll use the featherweight 16" barrel

Any comments on the above modifications?

May 21, 2003, 05:15 PM
Badger Arms,

Not sure where you get the CavArms lower is crap, it gets rave reviews at Their new lowers are A1 length, and the AR15 crew all seem to agree that they are the way to go for the lightest weight lower.

As to your other concerns, naturally when you lighten a barrel and make it thinner, it's going to heat up faster, if you want super accuracy, go for a 24" heavy barrel. For your stated purpose of a lightweight carbine for the kids, a CavArms lower with a Bushy lightweight upper sounds like the ticket to me.


Paul Gomez
May 21, 2003, 05:58 PM
Cav Arms lower are the bee's knees, particularly if you have them shorten the stock.

Another route would be the Stubby Stock from Bushy on a regular lower.

For the top-end, a Les Baer flattop upper with no provision for forward assist should cost around $90 and they don't get no lighter. Mate a Bushy SuperLightweight 16 barrel and call it a day.

My personal AR predates the Bushy SuperLightweight barrel. It's got a Wilson Match, profiled down to A1 dimensions and chopped to 14.5 prior to the vortex being mounted, but the end state is the same. It ways well under six pounds.

For a rear sight, the Canadian C7A1 backup sight works well (and ways nothing), but there are plenty of rear sights to choose form nowadays.

Badger Arms
May 21, 2003, 08:04 PM

My opinion of CavArms comes from personal experience. I have personally examined 5 lowers now and two rifles. ALL WERE ABSOLUTE CRAP in my opinion. I hear others say great things and I have to wonder if they have ever looked at one or if they are just relating second-hand experiences or what. I can't imagine that all 5 of the ones I've seen (from three diferent sources) were lemons and the the majority of guns out there are the cat's meow. What I observed were huge mold lines, improperly 'welds' between the two halves, warpage, bad lines, voids, and an all-around poor workmanship. You can mold a lower out of carbon-fiber reinforced plastic that works just like the current lower without the need for non-standard takedown and safety detents and without much hassle. I haven't seen a good one but I'll wait.

I might be wrong about CavArms but I want to see a good one in person and I doubt I'll be swayed by online arguments. Anybody up here have one? I'd love to eat crow on this one because I like the concept but I don't much like what I've seen execution wise. Enough said...

Now, as for the stock length, I'm pretty much set on the M-4 stock pinned to a short length. I don't like the stubby stocks because they are too short and I don't like the A2 or A1 stocks because they are too long. My choice on that one. I'd also like to make the guns 'non-kidlike' as they grow and perhaps lengthen them.

May 22, 2003, 11:14 AM
I remember GunDigest listed a weight of less than 6 pounds for the old Colt Lightweight model with 16" barrel. How did they do that?

It's kind of funny how heavy these rifles have gotten.

May 22, 2003, 11:34 AM
Carbon fiber handguard and ACE skeletonized stock?

May 22, 2003, 02:52 PM
Badger, I've got a Cav Arms lower. Unfortunatly I can't help you much since mine is a "factory 2nd" and it is butt ugly. Got it for $75 though. And it seems to work. Big mold lines, and dings but it holds the upper on while I shoot it. :)

May 22, 2003, 03:36 PM
I have a Cav Arms lower. I think it is terrific. In fact in all the posts I have ever read about Cav Arms lowers, I have read one that is negative. It also doesn't use any non-standard parts. I assembled it and know what parts are in it.
I have never weighed one, but I don't think it would be your best bet for the lightest weight rifle. I am putting together a lightweight AR right now. I am using a standard lower with an ACE ARBT stock. The stock is shown here:
I then sent a Bushmaster 16" upper to Kurt at KKF for his ultralight conversion.
One note on KKF. I sent him this upper in February and haven't gotten it back yet. If I am not mistaken, we deployed our troops, invaded Iraq, swept from one end of the country to the other, won the war, and have started sending our troops home in less time that it has taken Kurt to turn this upper down on a lathe and sent it back to me.

May 22, 2003, 04:11 PM
one would wonder what Bushmaster is going to be able to do with the PO polymer reciever technology they have aquired

a carbon wrapped barrel like ole St. Eugene had in the late 50s would be light too...

May 22, 2003, 04:20 PM

Just a quick note...

I keep reading that you plan to "pin an M4 stock" to your desired length.

Don't know if you're concerned with this, but technically, a true M4 stock is not BATF approved on a post-ban rifle, even if it's pinned in place, since it can be "unpinned", etc.

The post-ban tele-style stocks that are available now are not converted M4 stocks, they are built from the ground up to LOOK like the telescoping stocks, but cannot be made to telescope. They also use a full length buffer tube rather than the carbine.

I agree with others (and may have mentioned it already) that the ACE stocks are the lightest way to go for an ultralight AR, and are available in any length you want from 10.5" to full A2 length.

Check out their new "Ultra Lite" from Del-Ton (
9oz lighter than an A2 stock!

Badger Arms
May 22, 2003, 08:49 PM
Badger, I've got a Cav Arms lower. Unfortunatly I can't help you much since mine is a "factory 2nd" and it is butt ugly. Got it for $75 though. And it seems to work. Big mold lines, and dings but it holds the upper on while I shoot it.Now if you got a 'factory 2nd' then perhaps there are other factory seconds out there. Maybe those are the only ones I've had the chance to observe?

About the legality of pinning an M-4 stock, it's legal on a Bushmaster and Rock River gun, why wouldn't it be legal on mine? I've looked at these stocks and they are pinned in place with the hardware that adjusts them replaced with a screw. That is my plan. I don't have any intention of breaking the 'law' that covers this.

May 22, 2003, 10:00 PM
Don't know if you're concerned with this, but technically, a true M4 stock is not BATF approved on a post-ban rifle, even if it's pinned in place, since it can be "unpinned", etc.

That is not, to my understanding correct. My Oly has a "pinned" stock, which I could, and plan on, return to it's former telestocking glory with a few minutes of work, and a handful of small parts. I believe the term is that the stock has to be in a "permament" fixed position, or at least on that cannot be adjusted without the use of tools. Why bother forcing fixed molded stocks on rifles when you can buy a folded and put it on aftermarket anyways?

The MD AR-15 site it

Badger Arms
May 22, 2003, 10:22 PM
And the nice thing about them M-4 stocks is that the ribs hide where the pins were in the first place. You can epoxy and paint and, being down in a recess, the holes will be completely invisible.

May 22, 2003, 11:57 PM
the commercial stocks have been BATF approved as fixed stocks

you would not want an agent doing a 300 pound collapse test on your rights

Badger Arms
May 23, 2003, 12:27 AM
gun-Fucious, the Commercial stocks are IDENTICAL to one that is pinned in the home. IDENTICAL. I'm not risking anything. The precedent is the folding stocks for the SKS where you can buy a fixed or folding kit to convert them as you will. Me, I'm not going to cower in the corner trying to follow whatever rule you wish the ATF was enforcing. A fixed stock is a fixed stock regardless of whether or not I make it fixed or Bushmaster makes it fixed. I don't need a ruling on that and I'm not about to crawl to the BATF Technical Branch if I want to do it, I'll wait for the letter that says NOT to do it.

I'm not going to apologize, I get very emotional about this. The laws say that the stock cannot be a telescoping stock. It takes a hammer, punch, vice grips, a screw-driver, and the original parts to convert the stock back. Heck, you can make the gun full-auto with less effort but I'm SURE that that's illegal. I'm a law-abiding American. I read the law and it's clear. I read the opinions and they are clear too. I can pin the stock if I darn well please.

May 23, 2003, 11:28 AM
I've looked at these stocks and they are pinned in place with the hardware that adjusts them replaced with a screw.
Mind you, I'm only trying to help, and not argue at all...
But the "tele-style" stocks from Rock River and Bushmaster are NOT just regular ones pinned in place. The ones I have personally seen, handled, and fired have used a full length A2 buffer tube that extends all the way to the end of the butt in it's fixed "extended" position rather than the "Carbine" buffer tube that leaves a hollow area in the stock when it's extended. So even if you did somehow get it to move and telescope, the buffer tube would be sticking out the back at the original length the stock was before it was "jimmied" loose. I have 2 buddies with those stocks, 1 RRA and 1 Bushy, and they're both that way. Maybe the ones you've seen were indeed converted from pre-bans.

Messed Up Mike - Perhaps there's some specific process that ATF has approved for pinning those stocks in place, and I apologize if I'm not up on the latest. But I did read a reply from the ATF on that said a pre-ban telescoping stock was NOT an approved post-ban stock just because it had been pinned in place, since it could be unpinned.

Of course, it's silly (and sad) that we have to have this conversation in the first place. I think the telescoping stocks (unlike folders) are GREAT since you can quickly adjust LOP to fit the shooter. My 11 year old son couldn't shoot my pre-ban AR otherwise... I had to chop the stock on my 10/22 so he could shoot it. :(

May 23, 2003, 02:17 PM
Yeah, the ruling on what does and doesn't constitute a legal stcok aren't terribly clear or well thought out. My Oly is a pinned in place tele-stock, so logic dictates that one could pin a stock at any length they want. Ace boomtube stocks can be custom sized.
It's more of a BS law than substance anyway (suprise!). It is still legal to own an adjustable stock that changes your pull length for precision shooting. Before that sets of a flame war about adjustable stocks check on sight under the stocks heading and you'll see one right there. I believe the standard is the the stock length cannot be changed without the use of tools. Hell I'm not even sure the ATF knows what they want to enforce.

May 23, 2003, 03:16 PM
I wonder how the ATF delineates between an adjustable stock and a collapseable one?

EG: What's the cut off between the G3 collapsing stock and the MSG90 target stock? Both have a butt portion that can be quickly changed in length.

Badger Arms
May 24, 2003, 12:44 AM
Well I've done some thinking. Here's a product that might suffice for the stock issue but I'm still undecided: I can combine this with a 'tactical' stubby stock and I'm set. Not too radical in the looks department, will satisfy the BATF, can be adjusted for the kiddies, and I can add one of them stock spacers to give me another inch if I need one. Here's the problem, it weighs more, MUCH more. I found most of the specific information I needed on weight here:

I'm probably still going to go for the M4 buttstock but I think that the carbon-fiber / Fiberglass free-float tube that Armalite sells will save more weight up-front. That's over 2/10ths of a pound if I just use the Aluminum stock (because I'd be replacing the steel barrel nut)!

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