Dreams of a 5 lb. Ar10

So like the title says, I have been contemplating if building one that light weight is possible for a quite a while. I have read about others coming close but haven't found one quite that light weight. There are titanium parts for some of the components available, and there are some purpose machined lightweight upper and lower receivers. Carbon fiber barrels, not sure if an aluminum skeletonized hand guard would be best, plastic or perhaps carbon fiber. Any ideas? Anyone heard of one that light?

 

That would be no fun to shoot. 7 or 8 lbs is nice for a 308.

 

Sounds expensive and unpleasant to me but to each his own.

 

A 5lb 223 AR sounds a lot more fun than a 5lb 308 AR.

 

First item to address would be the carrier. Next would be receiver materials. Don't forget barrel contour and/ or materials.
plastic handguard would be the lightest

 

I add weight too centerfire rifles, not remove it. I like an 8.5-9 pound rifle.
This is light compared to my old muzzle loader.

 

.308 recoil is pretty tame. I can't imagine a 5# AR10 bring nearly as bad as a modern Ultralite bolt gun (Kimber Mountain Ascent, etc).

Camping gear, and women's swimwear. Call this the Bikini Build: Less is More.

 

I add weight too centerfire rifles, not remove it. I like an 8.5-9 pound rifle.
This is light compared to my old muzzle loader.

 

Chuck up the lightest barrel you can find and turn it down to 3/16 wall like a pencil barrel, except the gas port area. Use a .0625 wall aluminum tube as the forend. Take a normal upper reciever and mill the shell deflector off. Mill the forward assist off and weld the hole closed. And ditch the dust cover. Fashion a buttstock from 1/8" wall aluminum tube with a 3/16 flat plate welded to the end. Attach a rubber butt pad. Low pro gas block, carbine length. No flash hider or pic rails. Magpul plastic sights.


... hmm now you've got me thinking

 

Ar10 pistol might make the 5lb cut and be reasonably priced, but that’s cheating. The stock, barrel, and hand guard weight savings would be significant, but I’m not sure they would be enough to overcome the weight of a “brace”... and that muzzle blast would be awful.

 

Never seen one that light but a DPMS GII in the Compact Hunter configuration will be just under 7 lbs. I suspect you could shave another half pound off it with a lighter hand-guard and stock although you probably going to add it back with some type of optics. The GII guns are unique in that the bolt carrier is the same diameter as an AR-15. Helps keep the weight down and the size of the receiver.

 

Who said the Al tube couldn't have holes or slots? Plus the upper reciever mods will save ounces. Ounces turn into pounds. Any little bit adds up when you consider modifying 10 parts. The carbon fiber stuff is definitely lighter and prettier, but more expensive.

I wasnt aware you could get a .550 308 barrel, I was just guestimating off the dimensions of a thin barrel 257 Robert's I have. Come to think of it, that muzzle is under .500 diameter.

I was simply trying to go about it a different way than buying all the individual parts.

 

We may have been here before. @breastroker claimed a sub-5# build last year: https://www.thehighroad.org/index.php?threads/building-the-lightest-ar10-ever.822282/

 

Is an aluminum carrier even doable? I mean wouldn't it gouge and crack under 1000 rounds?

 

Getting one down to 6 pounds would be doable. I hunt with the mountain ascent in 308. It only weighs 5 pounds. With a muzzle brake the recoil is not bad. The gas gun would further reduce recoil.

 

And here I am building an AR-10 with a ~20lb target in mind...

 

Not mine, but how about a 4 lb .308 AR?



Link to thread (photo from page 96)

 

Flip flops are lighter than my boots, but lets just say I'm not giving up my boots.

 

Reading though that thread kind of makes me want to try a light build with a 16" 6.5 CM Faxon Gunner. The titanium BCG and lightweight upper/lower pairs really aren't as pricey as I thought. I bet I could cheapen up the furniture a bit and save a few hundred dollars, still coming in under 6lb. Not sure what I'd use it for, maybe hunting?