Super Lightweight AR Build

**K31** · January 22nd, 2018, 11:50 AM

Does anyone have a 4lb or sub 4lb 16in BBL AR chambered in 5.56? I’m curious as to what parts you used to get to that weight. Here is the list of parts I’m looking at to achieve a 4 pound build. I’m still up in the air about the handguard and weather or not to use an adjustable gas block because of the lighter weight BCG. I’m not running a suppressor on this rig so I don’t think it matters much as I can control the bolt with a heaver weight buffer if needed.

This is a hell of a combination and anything but cheap to say the least! All weights were taken from the manufacture of the parts. The only steel parts are the barrel, trigger, hammer, sear, bolt, gas tube and buffer spring.

Lower Receiver:

Battle Arms Lower Weight: 6.84oz
Geissele Super 3 Gun Weight: 2.1oz
Battle Arms Titanium Take Down Pin Set Weight: 0.2oz
Battle Arms Development Bolt Catch Weight: 0.3oz
V Seven Titanium Mag Catch / Release Weight: 7.4 gram
V Seven Titanium AMBI Selector Weight: 11.7 gram
V Seven Titanium Trigger / Hammer Pins Weight: 2.3 gram
V Seven Titanium Buffer Retainer Pin Weight: 1.1 gram (total grams 22.5) =.79oz
Sabertube Mid Length Stock QD Weight: 6.8oz
Standard Weight M4 Carbine Buffer Weight: 2.8oz
Strike Industries AR Flat Wire Spring Weight: 1.6oz
Magpul K grip Weight: 2.2oz

Total Lower Weight: 23.5oz or 1.46lb

Upper Receiver:

Battle Arms Upper Weight: 6.3oz
Faxon 16" PENCIL, 5.56 NATO, Mid-Length Weight: 1.20lb
Battle Arms Titanium Gas Block .625 Weight: 0.4oz
V Seven AR-15 Titanium BCG Weight: 5.6oz
A2 Armament T3 Titanium Comp Weight: 1.3oz
Brigand Arms Atlas 12” Carbon Fiber rail Weight: 6.6oz
Mid Length Gas Tube Weight: 0.1oz

Total upper Weight: 39.5oz or 2.4lb

Total Rifle Weight: 3.86lb !!!!!!

**gghbi** · January 22nd, 2018, 01:13 PM

If you search Empty Mag did one for his wife (in Purple) complete with pictures. I do not remember exactly how much it ended up at.

http://forum.pafoa.org/showthread.php?t=320603

**NathanB** · January 22nd, 2018, 01:45 PM

I do. The 2a armament stuff is lighter but mine is a pinned 14.5

**NathanB** · January 22nd, 2018, 01:55 PM

The three main brands as you’ve found out are
V7
Battle arms and
2a armament. They are the ones focusing on the lightweight stuff. Mine is all 2a and v7
receiver set 6.50 oz 5.85 oz
takedown pins 5 grams
bolt catch 9 grams
safety selector 9.5 grams
endplate 5.5 grams
castle nut 6.7 grams
tube detent 1.1 grams
buffer tube 3.6 oz
mag release 4.9 grams
grip screw 3.2 grams
port door 8.3 grams
door rod 2.2 grams
buffer 2 oz
grip 3.8 oz
charging handle 29 grams
stock mft minimalist 5.6 oz
trigger ALG ACT QMS 3 pz
bolt 2a armament 7.9
rail 2a armament 7.95 oz
gas block .70 oz
gas tube 1 oz
barrel faxon firearms 1.09 lbs
muzzle device 1.35 oz

Trijicon MRO 6.08 OZ

4.713 lbs total with mro
Some of those are estimated weights and I think it came in lighter than that actually

I found the combo of the fixed titanium block and adjustable carrier was lighter than trying to do adjustable gas block and lightweight carrier. I’ve also got a configurable buffet to help. I should look into a lighter grip and cut an ounce or two but it’s light enough.

The budget for this went well over 3k

emptymag used a poly lower for his.

**danhr** · January 22nd, 2018, 01:55 PM

OP: how much did the build run you?

**NathanB** · January 22nd, 2018, 02:03 PM

Mine was over three grand by the time it was all said and done. It can be done a bit cheaper now. I’ve had mine for about two years.

I just checked. It was this time in 2016. So different ar climate. The bcg alone was 369 then

**Emptymag** · January 22nd, 2018, 02:23 PM

$369 BCG!!! I just spit my drink out!!!

LOL!

Yeah, mine is a poor man's lightweight. Probably cost $600 or so but it's probably a half an ounce heavier than any $3,000 gun. LOL!

It's cool though. If you have the funds and desire, go for it. I just can't rationalize spending 20x the price for a small titanium part just to save two tenths of an ounce.

The single most weight-saving thing that makes a real difference is the barrel - after that, it's all just an ounce here and a fraction of an ounce there.

**K31** · January 22nd, 2018, 02:24 PM

Originally Posted by danhr

OP: how much did the build run you?

All of my parts total $2066.54

• Battle Arms UPPER/LOWER SET Weight: 13.1oz Price: 500.00
• Faxon 16" PENCIL, 5.56 NATO, Mid-Length Weight: 1.20lb Price: 160.00
• V Seven AR-15 Titanium BCG Weight: 5.6oz Price: 348.00
• Rainier Arms Avalanche 2 Charging Handle Weight: 1.0oz Price: 79.00
• A2 Armament T3 Titanium Comp Weight: 1.3oz Price: 130.00
• Battle Arms Titanium Gas Block .625 Weight: 0.4oz Price: 79.00
• Brigand Arms Atlas 12” Carbon Fiber rail Weight: 6.6oz Price: 350.00
• Battle Arms Titanium Take Down Pin Set Weight: 0.2oz Price: 37.00
• Battle Arms Development Enhanced Bolt Catch Weight: .39oz Price: 13.95
• V Seven Titanium Buffer Retainer Pin Weight: 1.1gr Price: 6.79
• V Seven Titanium Mag Catch / Release Weight: 7.4gr Price: 37.98
• V Seven Titanium AMBI Selector Weight: 11.7gr Price: 66.93
• V Seven Titanium Trigger / Hammer Pins Weight: 2.3gr Price: 16.49
• Mid Length Gas Tube Weight: 0.1oz Price: 15.00
• Sabertube Mid Length Stock QD Weight: 6.8oz Price: 179.00
• Standard Weight M4 Carbine Buffer Weight: 2.8oz Price: 9.50
• Strike Industries AR Carbine Flat Wire Spring Weight: 1.6oz Price: 18.95
• Magpul K grip Weight: 2.2oz Price: 18.95
• Geissele Super 3 Gun Weight: 2.1oz Price: strip from another build

**Emptymag** · January 22nd, 2018, 02:32 PM

I used a Taccom lightweight buffer/spring.
Is it the best choice? I have no idea. Does it work? It does for me.

(the buffers are shipped in black now)
Adjustable gas block must be used with this.

https://taccom3g.com/product-categor...d-accessories/