Godspeed.

Thanks amigo. One more surgery to go, hopefully. It's been a long battle, but my wife is a fighter and young.

Prayers for you wife.  Stay strong for her!

2A titanium RBC in the EE

https://www.ar15.com/forums/equipment-exchange/FS-or-FT-KAC-ARMS-PSA-PWS-QC10-and-more/25-2250663/
its mine.

I have one of those as well, and may never use it. Maybe I should MP it. We'll see...

Making a 16" near featherweight:

Attached File

Anyone have a Fostech 10” Mach 2 rail?

The website list it as 4.42 oz, I’m guessing that does not include the barrel nut. Does anyone have an actual weight of this rail, nut and hardware? I’m not seeing it in the database…

I am curious as well, I was looking at the 13”

Spoke to Fostech today, all weights listed include the hardware.

That’s awesome, ordered one yesterday. Going to replace a MI SL 9.25” to shave another 4 oz.

Edit: it’s here…

Attached File


4.677 oz

The box and packing paper weighed more then this rail!

So it’s about 1/2 oz lighter than my 9” Clark Carbon and 4 oz lighter then my MI SL 9.25”

Will get it installed tonight or tomorrow…


Edit: in a few days… had to order a different crowfoot.

Yeah, I am wishing I had ordered one of these instead of the Guntech Air lite that’s arriving today.

Attached File



Attached File

How long is the 10” rail? Wondering if it will cover the gas block on a mid length

Excellent work everyone! Occasionally I'll contemplate shaving a few more oz off my build... it wouldn't be too hard. Mine is a pig compared to some of y'alls.

No, it would cover about the first 3/8” of the gas block on a middy.


From the end of the upper receiver to the longest point is 9.75”, the top of it is only 9.5”

Also there are 2 alignment tabs that sit on either side of the upper receiver rail. These are 1/8” long.

My SBR has a 10.5” Faxon pencil weight barrel for reference. This rail did not protrude past the shoulder for the barrel threads. If a suppressor or muzzle device that comes 90 deg off the barrel, it should clear the end of the rail by about 1/16”
On my Trek T the end is coned slightly giving the allusion there is more space there than there is.

As stated in the other thread. My SBR was 8# 8oz now under 5# 3oz. And still could shave a few oz. Changing to a Houge 15 deg grip and removing the buffer weights would drop about 3 oz.

Likely not till next year… my other LW build with the Fostech receiver set needs to get form 1ed. 10.5” barrel a few other tweaks and should be able to get it under 3# bare (under 4 with this can and optic). I don’t think it’ll require upgrading to a Ti or Al BCG.

I am going to be swapping my Umbrella Corp Grip with the Hogue 15 degree. I will weigh them both and see what kind of difference it is.

I am guessing around 0.9 - 1.1 oz difference.

Then I want to swap over to a Battellink MFT to save about 1.5 oz.

At that point getting lighter will require pretty expensive parts, but I should be around 5 lbs, 9 oz with a standard weight barrel, heavy muzzle device, and full bolt/carrier.

No archive!

So, a question.

Is the MFT Battellink the best cheap/lightweight stock you can get right now?

I thought it weighed 6oz, but their website says 10 oz now.

That's what I use in all my non-folder ARs.

I have a Fold AR that has to go on a diet, and convert from pistol to rifle.  How hard is the MFT to get on and off?  Otherwise I'll just use the little plastic CAR stock I have somewhere.

Easy as sin

It's been a few years but check this out.
Attached File


My rifle weighed in at 5 lbs 15.9 oz

Try the Rogers Super Stock, Spartan (loses a butt pad and QD mounts). Has a cam locking system that keeps the stock tight and is lighter than the MFT. The standard or 'deluxe' version is maybe a bit heavier but can be found for under $40 and you can always remove the butt pad to save a little weight.

Whoops already bought the MFT. It's ... OK.

Alright so there aren't many places I can save weight on my current build without basically doing a completely new upper. (I have a pinned and welded flash hider)

I have been thinking about a reduced-mass bolt carrier (currently using a full-auto BC).

What is your favorite reduced-mass bolt carrier?
If I do less mass on the BC, do I need to use a lighter buffer?
Can I just remove some weights from my current buffer?

Had an undergassed 27" rifle+3" gas gun, 1st experiment was to put the buffer in backwards.  That got me close to consistent running by removing the mass of the buffer.  I ended up pulling all the weights out of the buffer & running a lightweight carrier.

No point in running an lightweight carrier if you've not already removed mass from the buffer.

I've been eyeballing this setup right here:
Odinworks lightweight BCG + adjustable buffer.

https://www.odinworks.com/product-p/pk-os-abs-lite-223-bcg-lm.htm

Seems like a decent deal and a good product.

I put the money down for the JP Ultra LMOS AL carrier, and the Taccom Ultra lightweight carbine buffers way back when I made my lightweight rifle in like 2015.

https://jprifles.com/1.4.7_LMOS.php
https://www.tacticallink.com/taccom-ultra-lightweight-carbine-buffer-for-ar15.html

I also use a New Frontier Armory Polymer Trigger and hammer to reduce the wear on the LMOS bolt carrier.

https://www.newfrontierarmory.com/lightweight-polymer-lpk

I used the DSA sandcutter bcg with taccom delrin buffer and tubb flat wire spring.  cut a ton of weight, and recoil

Looking at DSA Sandcut vs. Odinworks Low Mass carrier

DSA Aluminum:  $159
5.21 Ounces
DSA Steel:  $129
9.1 Ounces

Odin: $229
9.0 Ounces
Adjustable Buffer included

I think my current BCG is 11.5 ounces so... not a huge savings to go with skeletonized steel.

Bump to prevent archive.

Spending $200 to save 2 oz seems a bit overkill haha.

Stupid question:
How hard is it to match the weight of a KE Arms KP-15 completed lower with a forged 8.5oz lower and carbine buffer?

Shouldn't be too hard.

Normally it would be

but this isn't for normal guns!

I got my ULW down into the 3lbs range, 4lbs with red dot and suppressor.  Took a lot of incremental steps to get there

Will likely get specific measurements and weights this weekend…

Fostech sells 2 rails that are advertised as 10”

The black one and the Tungsten one. They are not 10.” The black one is 9.75” and the tungsten is 10.5”

They even appear to be different lengths on their website…
Attached File


This actually works out for me. The Tungsten one was going to go on my SBR but now I’ll pull the black one off my 16” middy and use the tungsten on it, as it’ll now completely cover the gas block.

Update:

Attached File


Both are “10 in Mach 2 LITE” rails

The black one is 9.75” and 4.677 oz
The Tungsten one is 10.5” and 4.877 oz

Works for me since the longer one help cover the muddy gas block. Just strange they are both listed as being 10” rails when neither are 10” rails.

Have you contacted them? That seems.... odd.

Will be starting another light build soon this thread has great help

Thank Yall so much

Anything we can do to help. Ultralight builders of the world, unite!

Updated the V7 titanium gas block weights on page 1.


I have a pinned and welded 14.5" barrel and it's the gov't profile.

Thinking about a 14.5 or 13.9" Faxon with a V7 titanium gas block and then pinning the suppressor muzzle device on that.

It would save me 4.5 ounces over what I have now...

Find someone w/ a lathe & trim the weight off the front of your existing bbl?

Going to be selling my LW upper and thought I would give this thread a first look in case anyone is looking for a similar build. I'd rather not part it out unless I have a taker for every part. Rifle and build list:


 

Message me if you're interested in anything.

Myself and a few others on here have had barrels turned for weight reduction. It makes so much sense since it’s the single heaviest part on the gun.

I requested access to the spreadsheet. In the meantime, I'll take any advice on parts. I want a light of a rifle as possible without sacrificing reliability, and durability. So far it looks like Faxon pencil barrels and Fostech rails are the lightest, so I planned on starting there unless I missed something. I will probably build on regular receivers because I already have them, and eventually move to a lightweight set due to cost.

Are there any reliability sacrifices with low mass carriers and buffers? I would rather not mess with the operation if theres a possibility of it causing malfunctions or needing to chase gas system tuning.

Of course.  Everything lightweight is sacrificing some reliability from the mil spec.  Are you operating in a high sand environment?  In Arctic conditions?  Steel case?  Lower power ammo?

M4A1s are running full-auto steel carriers backed by H2 buffers w/ the heavy SOCOM profile bbls and a 1 lb bulletproof Aimpoint on top.  Do you want an 8 lb carbine?

I'd love an aluminum carrier and no weight buffer in my fold AR w/ a featherweight bbl b/c at the most I'll put 60 rounds through it in anger - I'm not strapping on a standard load of 210 rounds to go to the mall.

Very interested to hear your plans for this.

Dunno.  Think it's a mid-gas pencil Faxon, and we took more material off.  Since then, I picked up a Fold-AR upper that needs to go on a diet, also mid-gas w/ an adjustable gas block and an adjustable carrier.  Of course, the Faxon won't work in a Fold AR.  I was going to try to hit the Under 6 thread w/ the featherweight bbl & a KP-15 lower, along w/ adjustable gas and a no-weight buffer, but not much point now.

If you go with a lightweight operating system you NEED to have adjustable gas or it will be WORSE not better... and you tune it to lock the bolt back on empty at the minimum gas setting of the weakest ammo you will regularly shoot.

As for weight limits I am a reliability stickler. Aluminum and Titanium carriers are a no-no for me, as are buffers without deadblow weights. I use the JP LMOS and standard 3oz carbine buffer or the LWRC ultra compact buffer with one steel weight swapped and wont go lighter. AKA an actual STEEL carrier and a REAL buffer. This combination, when tuned with a titanium adjustable gas block and standard carbine spring to JUST lock the bolt with brass cased .223 55 grain ammo will litterally run anything any time. It just won't lock the bolt on the last round with weak steel cased ammo, but it will cycle it all day.

You won't get a 4lb AR with a LMOS and standard carbine buffer, but personally, I have found any AR under 5 lbs to shoot 5.56 increasingly worse due to the lack of weight. My lightweight 5.56 is just a smidge over 5 pounds with Aimpoint T1, BUIS, weapon light, batteries, and QD sling points installed. I might want to hit 4 pounds 15.9 ounces with everything on, including rail covers and flip off light diffuser installed, but I am unwilling to go to a pistol optic, uberlight carrier, non-adjustable titanium gas block, plastic FCG parts, or a non-deadblow buffer, so it will probably never get lighter and have to live its life in the 5-5.5 pound category forever.

The small frame AR15 shooting .223 has a VERY wide, forgiving acceptable mass range to be reliable in SEMI auto, shooting common .223 and 5.56 loads, IF you don't shoot full auto, IF you don't shoot suppressed, and IF you clean your rifle every range trip.

People with no internal weight or plastic buffers with aluminum carriers ALWAYS show signs of early extraction. Every rifle I have seen with a titanium carrier and lightweight buffer tuned to run .223 shows signs of early extraction and bounces the brass of 77 grain 5.56 off of the brass deflector. Add a can and you are continually at the teetering edge of failure. Such set ups will NOT shoot full auto with anything, even when the carrier is correctly dimensioned or modified to trip an auto sear or lightning link.

To each his own (and I respect the ALL IN lightweight nuts who really push the edge) but I prefer a reliable lightweight rifle that shoots well over a twitchy ultra featherweight with occasional reliability issues.

 I discovered the joys of the no weight buffer w/ lightweight steel carrier when trying to get my daughter's 27" pencil bbl w/ rifle + 3" gas to run.  W/ XM193 and the adjustable gas wide open it runs, think it is bouncing the brass off the Brunton bump, but it's been a long time.  It wouldn't run reliably w/o pulling weights out of the buffer & a lightweight carrier.  I doubt it's extracting early.

For the price, the Unbranded AR Billet 7075 Receiver set is an excellent option for lightweight on a budget. Scored 2 of them Black Friday deal for $161 each shipped. Although I'm a lefty, it also has a PDQ ambi bolt release.

Just found this butt stock option! Anyone wanna try it?

RC blade works stock