Ultralight Ultralight Rifles

[StupidLightweight]

As the owner of a beautiful 6mm ARC straight-pull barrel, I suggest staying with .223-based cases like others are saying. The added recoil and likelihood of difficult chambering ain't worth it. My suggestions would be:
1. .223 Wylde
2. 6x45 (if .22 centerfires aren't legal in your state and you handload)
3. .25-45 Sharps
4. .300 HAM'R
5. .350 Legend
6. .300 BLK

 

[PistolPete]

Can't help but think a Solo would be a great platform to launch subsonic 450 Bushmasters from, like my 385 gr HP's - almost like a modernized 4 lb 45/70. Wouldn't want any part of the supersonic full-bore loads though!

 

[Thegman]

You may be in luck. I think Solo may be going to offer 450 Bushmaster rifle barrels specifically for the Solo300. I don't think I'd be interested, but there may be a lot of guys like you, for whom it would be a good option.

 

[TML75]

A 12.5” 5.56 barrel would be perfect for me, but I know not many people want that length.

 

[Thegman]

A 12.5” 5.56 barrel would be perfect for me, but I know not many people want that length.

You're probably right, but would make a nice super light suppressed SBR.

 

[Hackleback]

Lead on a reasonable priced alum gas block I can carve on?

 

[Thegman]

AR-15 .625 Diameter Aluminum Low Profile Barrel Gas Block

AR-15 .625 Diameter Aluminum Low Profile Barrel Gas Block by GUNTEC .625 Diameter T6 Aluminum Two Set Screws Roll Pin Included

www.midsouthshooterssupply.com

Low Profile Silver Aluminum Gas Block- .750" Diameter | MADE IN U.S.A

Features:0.750 DiameterMil-Spec DimensionMaterial: Aluminum ConstructionAnodized SilverFits: AR 750'' Barrels *NOT Designed For Bull Barrels

outdoorsportsusa.com

Gas Block .625" Mini Low Profile Micro Gas Block -Black for AR15 223 5.56 (625GB)

AR15 223 5.566061-T6 High Quality Aluminum Low Profile Gas Block Come With Roll PinFits 0.625" Barrel and Standard Gas Tube Precision Machined from Alumi...

www.ar15handguard.com

Not sure what size you need. Mid south has both .625 and .750. I've purchased from them before, but not the other two I linked.

 

[Hackleback]

Some light weight barrels

The Bear Creek for those on a budget (out of stock now)
Faxon looks interesting at 19 oz (1.2 lbs) Any reviews on this one ?

Lightweight AR 15 Barrels | Lightweight AR 15 Parts

Experience precision and agility with our Lightweight AR 15 Barrels. Reduced weight, enhanced maneuverability, and improved accuracy for optimal performance.

blackrifledepot.com

 

[StupidLightweight]

The Faxon pencil barrel is the modern originator and well liked. I've not messed with them, but I've not heard anything bad.

 

[Thegman]

I have both the Faxon 5.56 pencil barrel, on my lightweight gasser, and their 223 Wylde match pencil currently on the "red ryder" in this thread.

Both shoot well, but I've shot more through the 5.56 barrel. It has shot some of the smallest 3-shot groups I've ever shot, like 3/16"@100 yards with 55TTSX. I don't think it has ever shot that load over or even at 3/4" for 3.

77TMK in the Wylde barrel doesn't do quite as well, but it put 8 shots into 1 1/4" @ 100 when I last shot it, so good potential. I've not messed with too much load development in that barrel though and have only used the 77TMK and 75 ELDM. I imagine it will shoot as well as the other.

I have 4 faxon barrels, they all shoot well. I have three Wilson barrels, they also all shoot well. All seven will shoot sub moa for 3 rounds.

If you get any of these barrels and can't find a MOA load, my first guess at the problem would be something other than the barrel, they all seem to consistently shoot well, IME.

 

[Superdoo]

How does the KE mono lower weight compared to building with aluminum and a light weight adjustable stock?
Is it worth my time to go track down pieces for a build if I want to stay below $2000 on total rifle cost?

I’m looking at putting together a 6 arc and making it as light as reasonable. 4.5 pounds would be great.

 

[StupidLightweight]

Superdoo, I can't answer that question. But I must say that I'm a big fan of the KE Arms polymer lowers. They're my favorite due to value. They may not be as light as other lowers and the length is fixed, but they are strong, cheap, and have very little to go wrong. Go for it. One thing many people get wrong about ultralight builds is you can go too far. There's always a sacrifice. To me, the only sacrifice with the KP-15 is a few ounces of weight and the fixed length.

Are you building a straight-pull or keeping it a semi?

 

[4090Sharps]

How does the KE mono lower weight compared to building with aluminum and a light weight adjustable stock?
Is it worth my time to go track down pieces for a build if I want to stay below $2000 on total rifle cost?

I’m looking at putting together a 6 arc and making it as light as reasonable. 4.5 pounds would be great.

I think over the standard carbine lower with adjustable stock you'll save 4-8 oz with the KE mono lower. A non-adjustable stock like Smoke Composites will drop even more weight.

 

[Thegman]

The KP-15 should easily make a 4.5 pound rifle for you. They seem simple, strong, durable and I've not handled one, but look like they have good ergonomics. $2000 should be more than enough. You should have about 1K or so left over when you're finished.

 

[Superdoo]

Are you building a straight-pull or keeping it a semi?

I was originally thinking straight pull, but now thinking of keeping it semiauto. How many ounces does a guy shave is you go with a straight pull?

 

[Superdoo]

I think over the standard carbine lower with adjustable stock you'll save 4-8 oz with the KE mono lower. A non-adjustable stock like Smoke Composites will drop even more weight.

Thanks. I’m just trying to decide if I should simplify my build or go full custom to optimize personal ergonomics and weight.

 

[Thegman]

Thanks. I’m just trying to decide if I should simplify my build or go full custom to optimize personal ergonomics and weight.

Assuming you'd be running an aluminum bolt carrier (DSA makes a good one and it's very lightweight and relatively inexpensive), and then figure in the buffer, buffer spring, gas tube and adjustable gas block, you'd probably be adding only about 5 or a bit over 6 oz over the straight pull, assuming you keep all those other parts as light as possible.

My gasser is set up very similar to some of my straight pulls and it weighs about 6 oz more, so not too much unless you're trying to go as light as possible, which it doesn't sound like you're trying to do.

If semi-auto is a feature you really want, I'd think it's worth the little extra weight, especially if you're only trying to hit 4.5 pounds, that's pretty easy to do on the budget you're thinking about.

 

[StupidLightweight]

Thegman knows his ultralight ARs. Listen to him. Build a semi to begin with and don't break the bank with crazy expensive parts. Afterwards, you can go balls to the wall and build an even lighter straight-pull. They're fun as hell and unique but offer no advantage for most shooters/hunters.

 

[StupidLightweight]

Any update on the Shaw barrels?

The Shaw Barrel arrived today. No gas port, beautiful fluting. But...at 1 pound, 15 ounces, it's far heavier than anticipated. Back to the drawing board for a factory option for us ultralight, straight-pull weirdos.

 

[Thegman]

The Shaw Barrel arrived today. No gas port, beautiful fluting. But...at 1 pound, 15 ounces, it's far heavier than anticipated. Back to the drawing board for a factory option for us ultralight, straight-pull weirdos.

Thanks for the update! It's too bad they didn't come up with something lighter than that. Going to the trouble of fluting the barrel, it would have been nice if they'd just gone with a much thinner profile instead...oh well, the search continues...