just curious what weights you (in general are coming up with) im not an ar guy but my brother assembled one for me that loaded with a 10 round mag and a sig sauer red dot came out to 5.11 lbs its a handy atv gun for sure

I built one for a customer back around 2000, using a Professional Ordnance Carbon-15 host. It had a 17 Mach-IV barrel on it that was .375" in diameter.
The customer claimed that it shot sub-moa. Weight was just under 4 pounds. That was with a standard BCG and Buffer. If those were both lightweight, it might have gone under 3.5 pounds.

Tony Rumore
Tromix

Edited to add: It was really ugly.

What parts make it light?
What parts make it heavy?

I have nothing left but pencil barrels which is a good start but I would rather have utility than the lightest weight. Mine wind up being around 8 lbs with a full 20 round mag, light, red dot, SOPMOD stock, BUIS’s and sling. I also carry batteries and oil in the tubes.

I’ll have to weigh my SBR but I bet it’s over 7.

But my buddy built one with a Faxon super light barrel, 13” light weight MI hand guard, a Leupold 1-4 scope in an Aero mount and WOTG sling. Without a loaded mag it weighs just under 6 lbs.

The barrel, FH, rail and stock is where most of the weight can be shaved.

I could have knocked off another 4-5 oz with a lighter stock.

6 lb, 6 oz as as shown...................light enough for everyday use.

MM

i made one down in the mid 3lb range

the blue print came from the owner of enlightened equipment quilts that did a write up on rokslide

you have to give me a pass on deets it's been 6 years now i think. maybe 7.

pencil profile 16" falcon barrel.

fostech upper and lower

dsa lightweight carrier

a 3d printed stock that mounted to a rifle length buffer.

smoke composites barrel nut and a simple piece of carbon fibre tube slipped over and epoxied in place

ran a 2x ACOG and then swapped for japanese sightron 3-9 mil dot in a aero precision mount.

thing actually ran quite well and shot pretty okay.

that's a crazy heavy handguard too. swap it out for the new one from hogue that's weighs 4oz, run a chopped MFT and a faxon pencil barrel and you be under 5 almost for sure

This post got me to thinking but let’s get to the pics first.
What I consider a bare gun just over 7 lbs with irons popped up, a good light, sling, SOPMOD stock with extra batteries and a sold rail that is not the lightest but is one of the strongest.

But loaded down with a full mag and added the Trijicon 1-6 it weighs 9.5 lbs yet is balanced very well and can handle any task. I had it figured at just over 8 lbs in my head.

Yes they can be built lighter but I had a BCM KMR rail bend on me, I like the heavy SOPMOD stocks and I could run a lighter buffer. I also need a light so after trying a few I settled on this Arisaka 300 series that weighs about 4 oz but gives me enough light to easily see and shoot out to 100 yards, probably further.

Me being one that has Kimber Montana’s for my bolt guns, I’m carrying a pig for a night gun. But it works for me.

I'm not going to use either plastic or graphite HG's but Midwest does make some metal HG's that get under 10 oz for a 13.5" HG.

The one in the pic is a Geiselle that is a MK 14, 13.5" & weighs 11.5 oz with the barrel nut as I recall. I like the longer barrel nut that Geiselle uses as it provides a lot of rigidity to the rail.

Yes, I've used the MFT stocks on a couple of others & they work fine for me; this was what I have available at the time.

MM

I still need to weigh mine, but it feels about the same weight and balance as my 10/22. 18" faxon gunner barrel, one of B. King's 13.5" handguards, aero receivers, A1 stock and grip, iron sights, pretty standard buffer/bcg.

I have one that sits right at 6lbs without a mag/ammo - pencil barrel, Rogers Super Stock, ltwt bcg, 11” SLR ultralight handguard, Aimpoint micro, …. It takes some serious planning on parts to build one much lower than that. I could cut prob 6-8oz off of it by swapping out the flash hider (Silencerco ASR), gas block (SLR adjustable) and handguard, but any more than that would start to get $$$. I would love to see folks build specs for rifle 5.5lbs and under to learn where weight is being reduced from what I’ve done on this one.

Easy to get to 5.5 pounds but dollar per oz after that start adding up.

Mine weighed out at 6lb even. Respectable enough for me

PSA Magpull stock and lower parts kit $99, PSA lower $49, CDNN 1-8 16"223 upper pencil barrel upper Bushmaster $199, CDNN BCG and charging handle $89 6# 1.8 ounces total weight no mag.. No optics $436