Ultralight Ultralight Rifles

[PistolPete]

19.2 oz 5.56 barrel for $80, don't know anything about the brand...

18446 - NBS 16" 5.56 NATO 1:7 Twist Black Nitride Mid-Length Pencil Barrel - AR15Discounts

This 16” Pencil Nitride / Melonite barrel from NBS is chambered in 5.56 NATO with 1:7 twist rate. Buy with confidence, all barrels are backed by our satisfaction and low price guarantee. Get it now!

ar15discounts.com

 

[ericacymcdonald]

I've been looking into a ultralight build and came across this spreadsheet on Reddit with parts weight. I didn't make it and I'm not sure how updated it is but it is pretty handy

AR15 Parts Weights Database

Welcome The PWD Welcome to the AR15 Parts Weights Database. I'm your host, jekbrown. This Google Sheet is an archive of part weight data with the objective of serving as a part-selection tool for the custom AR assembler. In addition to weights, other useful information has been archived in the P...

docs.google.com

 

[Thegman]

19.2 oz 5.56 barrel for $80, don't know anything about the brand...

18446 - NBS 16" 5.56 NATO 1:7 Twist Black Nitride Mid-Length Pencil Barrel - AR15Discounts

This 16” Pencil Nitride / Melonite barrel from NBS is chambered in 5.56 NATO with 1:7 twist rate. Buy with confidence, all barrels are backed by our satisfaction and low price guarantee. Get it now!

ar15discounts.com

That's lighter than what they used to offer. Thanks for the heads up on that. At that price I might try one just to see if it will shoot 75 ELDMs, if not, sell for $50...

 

[Thegman]

I've been looking into a ultralight build and came across this spreadsheet on Reddit with parts weight. I didn't make it and I'm not sure how updated it is but it is pretty handy

AR15 Parts Weights Database

Welcome The PWD Welcome to the AR15 Parts Weights Database. I'm your host, jekbrown. This Google Sheet is an archive of part weight data with the objective of serving as a part-selection tool for the custom AR assembler. In addition to weights, other useful information has been archived in the P...

docs.google.com

Yes, that's a super helpful resource. It gets a little dated as new AR stuff comes out so fast, and old AR stuff changes so fast, but it's a really helpful foundation.

 

[PistolPete]

That's lighter than what they used to offer. Thanks for the heads up on that. At that price I might try one just to see if it will shoot 75 ELDMs, if not, sell for $50...

What does the 75 ELDM offer that the 73 or 77 TMK don't?

 

[Thegman]

What does the 75 ELDM offer that the 73 or 77 TMK don't?

Good question. Nothing very important in all honesty. Cheaper than TMKs and better BC than the 73 grain. I guess mostly because I have some and it would give me another bullet to test out, and I can get them really cheap locally, but neither of the other two.

 

[StupidLightweight]

I'm disappointed in Thegman's bullet selection. By using the 69-grain TMK instead of the 75 ELD-Ms, he'd save .014 ounce per bullet! That's a lotta unnecessary weight going up a mountain. With a 10-round mag, that's an extra .137 ounces!

I say the above in jest, but in all seriousness, the 69-grain TMK is one I'd like to play with. Should be easier get, cheaper, and plenty lethal for the game and distances I shoot.

Happy New Year, everyone! I hope 2024 brings you joy, happiness, and your lightest straight-pull ARs yet.

 

[PistolPete]

H

I'm disappointed in Thegman's bullet selection. By using the 69-grain TMK instead of the 75 ELD-Ms, he'd save .014 ounce per bullet! That's a lotta unnecessary weight going up a mountain. With a 10-round mag, that's an extra .137 ounces!

I say the above in jest, but in all seriousness, the 69-grain TMK is one I'd like to play with. Should be easier get, cheaper, and plenty lethal for the game and distances I shoot.

Happy New Year, everyone! I hope 2024 brings you joy, happiness, and your lightest straight-pull ARs yet.

I picked up some of the 75 gr RMR BTHPs, at 17 cents each they'll be great practice anyway...

 

[packgoatguy]

Sorry if this has been covered before; but between the Faxon 223 wylde 1:8 twist barrel and the Wilson Combat 5.56 NATO chambered pencil barrels, which one has been more accurate shooting the 77TMKs, 73s, and 75 eldms? I would also be interested in a report on how the cheap NBS barrel noted above does as well.

Generally speaking, for those of you used to shooting AR15s, is there a difference in accuracy between a 223 wylde chamber and a 5.56 chamber? Both could shoot regular 223 REM and 5.56 factory ammo correct? Can one or the other be loaded hotter?

Any difference between the 1:7 twist and the 1:8 twist options in these pencil barrels accuracy-wise? Again, assuming the 77gr tmk. Although, the new hornady 80gr ELDX bullets look like something to try...

 

[packgoatguy]

Does anyone have an accurate weight on the New Frontier Armory complete LW-4 lower without the stock? (without the milspec stock, buffertube, buffer, spring, and castle nut).

Also, what is the difference between the NFA LW15 and LW4 lowers? is one lighter or stronger than the other?

Last dumb question:

Between the Tennessee Arms carbon lower and the NFA LW4, which one would come out lighter weight in the end? Say, put a KAK LPK in the TN Arms lower and the lightweight polymer LPK in the LW4, which is lighter? more durable?

 

[packgoatguy]

For those of you with experience shooting these ultralight ARs, What is the best trigger and trigger weight you've found for eeking out the best accuracy as possible?

 

[PistolPete]

Does anyone have an accurate weight on the New Frontier Armory complete LW-4 lower without the stock? (without the milspec stock, buffertube, buffer, spring, and castle nut).

Also, what is the difference between the NFA LW15 and LW4 lowers? is one lighter or stronger than the other?

Last dumb question:

Between the Tennessee Arms carbon lower and the NFA LW4, which one would come out lighter weight in the end? Say, put a KAK LPK in the TN Arms lower and the lightweight polymer LPK in the LW4, which is lighter? more durable?

My complete LW4 lower, with polymer LPK, and no stock/buffer tube etc, is 8 oz. I'd imagine TN Arms would come in a little higher than that, but also be potentially more durable with the metal buffer tube threads.

 

[packgoatguy]

My complete LW4 lower, with polymer LPK, and no stock/buffer tube etc, is 8 oz. I'd imagine TN Arms would come in a little higher than that, but also be potentially more durable with the metal buffer tube threads.

Dang, thats pretty close to my estimate just subtracting off the weight of the mil spec stock parts from their advertised weight of 27.52oz for the complete lower... I was at 7.84oz lol!

Im mainly curious because that Google Sheets link shows the TN Arms lower (bare) as a tenth of an ounce lighter than the LW4, even though it has the metal threads.

So, if my math is correct then, the NFA polymer LPK is about 4.14-4.30oz including grip and trigger assembly... how does that compare to the KAK LPK or even a standard mil spec metal LPK? (assuming still using the lightweight polymer grip)

 

[packgoatguy]

My complete LW4 lower, with polymer LPK, and no stock/buffer tube etc, is 8 oz. I'd imagine TN Arms would come in a little higher than that, but also be potentially more durable with the metal buffer tube threads.

How much does the polymer grip and grip screw in the NFA lpk weigh? Ive got a steel grip screw that came with an MDT stock for a bolt rifle, and it is 6 grams... but I see the tactical link titanium grip screw advertised at 3.2 grams, for like $12. Not sure how that compares with the one that comes with the LPK. The carbon fiber grip on that stock is 28 grams, or .987 ounces, also interested to know how that compares to the poly grip in the lpk.

 

[JBradley500]

What red dot would be light and affordable for one of these? I have the parts coming, minus optic and sling.

 

[packgoatguy]

What red dot would be light and affordable for one of these? I have the parts coming, minus optic and sling.

Don't know about affordable... but the trijicon sro is the only 1MOA red dot I could find, which helps to be more precise with shots. It also has held zero when my vortex venom did not... 4.1oz including the trijicon brand picatinny mount (I tried the cheaper knock off mount first... it did not hold zero... but the trijicon brand one does)

 

[JBradley500]

Another question: what normal parts are you not using when you do a Solo 300? The bolt catch? The buffer retaining stuff? Anything else you skip or don't skip?

 

[Silent_Matt]

Here's my lightweight straight pull. I've been wanting to build one for a while, but was worried about primary extraction issues(not an issue at all). I picked up a couple BA Pencil barrels and a couple Trigger Tech Competitive triggers during the black Friday sales. It weighs 5lbs 4oz with the Vortex Spitfire 5x and shoots great. I originally milled the upper for left hand charging, but liked right handed better.

 

[StupidLightweight]

Great work, Silent Matt. That's a pretty rifle. Share more pics and give us a build list. I'm especially interested in that stock!

 

[Silent_Matt]

Thanks. The stock is a Jmac knock-off and the stock adapter is from KNS. It has a polymer lower, BCA upper, MOE SL grip, and an unknown handguard with an aluminum barrel nut that I had laying around. I machined the Delrin cheek riser and the single port brake.

This pic is in left hand configuration.