What is considered to be a lightweight AR?

[Ibmikey]

Having just completed a light weight project where i hoped to keep the rifle right at six pounds utilizing standard ( not expensive LW carrier etc.) but quality parts. I think i have achieved my goal and the initial test fire of two hundred rounds found the rifle to function correctly and accurately even after heating the barrel. My initial break in was at 28 degrees with a wind of approximately eight mph necessitating warm clothing and gloved hands.
The rifle:
Aero Precision Gen II lower with screw to take up any slop.
Rogers Super Stock ( slightly lighter than CTR )
ALG Ergonomic V2 rail 13" long ( could have dropped weight with shorter rail)
Faxon light weight gas block
Nitromet gas tube
Faxon upper receiver with skeletonized shell deflector
troy fixed sights
Faxon pencil barrel 416R stainless QPQ treated mid length gas
ALG Sidewinder brake ( small diameter and heavily ported nitride SS)
ALG lower parts kit with ACT fire control group
Aim nii boron enhanced carrier with Faxon QPQ bolt
Colt H2 buffer
Midwest Ind clamp on loop for single point carry (aluminum)
I could have cropped a few ounces with a 14.5" barrel and shorter rail but this is a build designed to eat a lot of ammo without break downs so i did what i feel will be reliable through a lot of shooting without attention.

 

[RogueNathan]

A Faxon pencil barrel and gas block, 12" Midwest or BCM rail, Daniel Defense sights and a MFT stock will get you in the 5.5lb range without breaking a sweat (or the bank). Start adding fancy lightweight receivers, titanium small parts, lightweight bcg's, titanium muzzle device, titanium barrel nut, etc and your cost starts to go waaaay up. It costs roughly double to go from a 5.5lb down to a 4.5lb rifle.

Also, optics are an area that holds a lot of hidden weight. My Aero Precision extended mount AND my Leupold 1.5-4x scope weigh a combined 12.5 oz. Compare that to a Vortex Strike Eagle (less clear, more expensive, worse eye relief and worse eyebox than the Leupy) at 17.5oz without mount.

Yep. Lightest barrels out there and proud of them. Send a photo, please!

 

[Jackal]

Yep. Lightest barrels out there and proud of them. Send a photo, please!

My last build was a 6lb (with MFT stock, not the pictured Magpul) 20" lightweight using the Faxon 20" Gunner barrel. I'm a fan. I've used 3 Faxon barrels now. Faxon and LaRue are my go-to barrel sources.

 

[Ibmikey]

Faxon and Aero Precision (ballistic Advantage) are my most used barrels, excellent quallity and extremelly accurate while priced in an affordable level. Many useful profiles are another strong point.

 

[RogueNathan]

My last build was a 6lb (with MFT stock, not the pictured Magpul) 20" lightweight using the Faxon 20" Gunner barrel. I'm a fan. I've used 3 Faxon barrels now. Faxon and LaRue are my go-to barrel sources.

Nice choice with the rail. Looks great!