Superlightweight AR15 build

[Arizona_Mike]

Not afraid to spend a little money on the novelty. I'm thinking polymer, carbon fiber, or magnesium lower. Adams Arms low mass bolt carrier (DI version) (with lightweight buffer and adj gas block to get the gas right), 14.5-14.7" pinned 0.625" pencil carbine barrel, left over no-FA/no-cover upper from a Colt Light Rifle (LE6900) I am not using (I do prefer a cover and am open to other really light uppers), carbon fiber hand guard.

Any idea who makes a good barrel with those specs? Preferably chromed, 1:8 (1:7 acceptable). What about uppers and lowers? I'm going to take my time and research parts. I'm not going to go as far as some and skeletonize a lower.

Mike

 

[G.barnes]

I'd get a good quality complete lower, bcm blemish lightweight complete upper and a lightweight aluminum freefloat handguard. I'd stick with regular internals for the bcg and buffer to keep from having reliability issues. If you run a 14.5 inch barrel with carbine gas system you don't need an adjustable gas block, it'll just be adding extra weight. You might save a pound going with a polymer lower.

 

[HOOfan_1]

This one should be pretty light

http://www.bravocompanyusa.com/BCM-...-WEIGHT-FLUTED-p/bcm-brl-mid-14-elw-f-std.htm

 

[dprice3844444]

http://www.gmriflebarrel.com/ar-15-m16-m4-rifle-barrels/ here's some nice barrels that are real shooters green mountain barrels

http://criterionbarrels.com/barrels/ar-15/ar-15-pencil

 

[blueskyjaunte]

I have had really good experiences with the CAV-15 lowers, now available at GWACS.

If you're in the Phoenix/East Valley area and want to try one out sometime feel free to drop me a line.

 

[mavracer]

You might save a pound going with a polymer lower.

Not sure how a forged lower is only ~8.5 oz.

 

[G.barnes]

I was being extremely optimistic giving it a full pound.

 

[Arizona_Mike]

I have had really good experiences with the CAV-15 lowers, now available at GWACS.

If you're in the Phoenix/East Valley area and want to try one out sometime feel free to drop me a line.

Looks nice! Nylon 6 (like a Glock) and 1.2-1.4 lb weight savings over a std lower, tube, and stock.

Mike

 

[taliv]

i got the bug to do an ultra lightweight build again last week. this is what i came up with on the 27th

total lb 4.8375
total oz 77.4

6.5 titane bcg
4.8 magtactical upper
5.9 magtactical lower
5.8 minimalist stock
23.9 BCM lightweight 16" bbl
10.6 rec ext/H buff/spring
1.5 BCM ch
2.6 geissele act trigger
2.1 lo pro gas block
2.6 WOA lpk
8.1 BCM 15" handguard
3 flashhider


( i'm missing a pistol grip though which is 2.9 oz)

but i could take a dremel and "lighten" some stuff too

however, adding a pound of weight would save about $1000, so it's hard to see the value here. i elected not to purchase.

this is my original super lightweight build

My old 3gun carbine (under 5 lbs)
17" carbon fiber barrel, titanium comp, carbon fiber upper/lower receivers, aluminum bolt carrier, JP trigger, clark custom carbon fiber float tube that i cut down

picture of it in this thread http://www.thehighroad.org/showthread.php?t=721584. it's the blue one

 

[Arizona_Mike]

I'd get a good quality complete lower, bcm blemish lightweight complete upper

Superlightweight AR15 build.

Not afraid to spend a little money on the novelty.

Mike

 

[Bartholomew Roberts]

If you want super lightweight, the new BCM fluted lightweight barrel with a KMR handguard is going to be tough to beat.

 

[gotigers]

Here's mine:

Sabre Defense lower
Timney 3.5lb Trigger
PSA LPK
Ace Ultra light stock
Tubbs spring
STD rifle buffer with replaced weights with an aluminum tube. 2.3oz
Aero Precision upper receiver, no door, no FA.
JP low mass carrier 6oz
BCM Gunfighter mod 3 CH
Rainier Arms medium contour 16", 1:8, 5r polygonal rifling, 30oz
Syra adj gas clamp on block
SJC Titan brake
AP Custom 12" carbon fiber tube, 5.4 oz
American Defense scope mount
Nikon Monarch 1-4x

It is 7.0lbs as shown. I could easily have got it under 6, if I didn't build it for 3 gun.

 

[SlowFuse]

I also like the cav-15 lowers. I have one of the original ones built by cavalry arms. It came stock on a Sabre Defence sr-15. That's a pretty light stock rifle. Also have one of the mkII lowers that is built by GWACS. They bought the tooling and rights to the original designs. The seams are a little more rough on the GWACS but seem to be just as durable.

 

[jakk280rem]

VLTOR makes a version of the MUR-1 that has a dust cover but no forward assist that is lighter than a standard upper.

 

[ifit]

Another lower to consider if you want to go aluminum is 2A Armaments Balios-Lite lower, it weighs only 6.50 oz, 3-D machined from certified 7075-T6 aluminum. I was amazed on how light the thing is. My lower is completed, now to build the upper

 

[crazysccrmd]

http://68forums.com/forums/showthread.php?50555-Building-a-light-weight-AR15-M4-MSR

4.5 pound 6.8 SPC, 16 inch Match grade barrel

UPPER
Wilson Combat 16 inch 6.8 SPC weighs 24.8 ounces
Anderson Slick Side- Upper no forward assist, no dust cover
ARP Shorty Brake 1.15 oz
V7 gas block titanium 0.80 oz
V7 titanium barrel nut 0.6 ounces
Mid length gas tube 0.75 oz
JP LMOS Carrier 6.8 oz. 6.8 bolt+ firing pin+ cam pin + 2.0 Charging handle 1.3 oz.

LOWER
Action spring 2.0 oz.
Carbine buffer at 1.7 ounces
Mag Tac lower receiver
Accu-group trigger 0.3 ounces
V7 aluminum buffer tube 3.5 ounces
MagPul K grip 2.0 ounces
Titanium grip screw 0.15 ounces
Titanium takedown pins
Rogers Super Stoc Spartan 5.0 ounces

 

[IslandTimes]

Check out V7 weapon systems, the guy has a bunch of super lightweight parts, but for a bit of a premium. Additionally, if you go with the mag tactical upper and lowers, Strike Industries sells a polymer dust cover that weighs the same as the more expensive V7 dust cover.

 

[Arizona_Mike]

I also like the cav-15 lowers. I have one of the original ones built by cavalry arms. It came stock on a Sabre Defence sr-15. That's a pretty light stock rifle. Also have one of the mkII lowers that is built by GWACS. They bought the tooling and rights to the original designs. The seams are a little more rough on the GWACS but seem to be just as durable.

Is it true that the originals were A2 length (13 5/8" LoP) and the later copies A1 length (13" LoP)?

Mike

 

[SlowFuse]

Mike, I wasn't sure so I went to measure.

The Cav that came on the Sabre Defence and the GWACS are identical in dimensions. Both having a 13" LOP.

I snapped a pic but couldn't get my photo bucket to work.

 

[jim243]

This one started out at 5.5 lbs.

Jim

 

[Unlicensed Dremel]

Handguard from Christensen Arms of Utah for sure (carbon fiber but has one lower rail built in).

Barrel possibly also from Christensen (carbon fiber wrapped). But if not a 16" CF wrapped bbl, then an 11.5" bbl - SBR it (preferably in 6.8 spc or .300 blk)

Polymer lower - hey people make fun of them but they DO save a bit of weight (IIRC, just over a quarter of a pound). You've got to at least consider it, if it's to be a true superlight.

Sight: Definitely a Trijicon RMI-DI with 12 MOA triangle.

I like that ACE ultra-light stock; seems like a good choice.

Upper: One without a forward assist - maybe not deflector either.

The rest is nibbling around the edges - you save or gain big weight with big items: Barrel, lower, upper, sight choice, handguard, buttstock.