*** LAST UPDATE 4/14/2024 ***
This is intended to help people who want to build lightweight rifles and/or want to lighten up an existing rifle. This is not necessarily intended to be a comprehensive list, as it only includes parts that are lightweight or nearly so.

RAW DATA SPREADSHEET HERE, v1.03

An updated Parts Database made by another user is here:  
Check this Google Doc
It may be more complete / more updated.

My recommended cheap / light build if you only want to get under 5 lbs for ~ $1k.


For a little more money (about $150 more) you can save a few more ounces


Key:
U = User Data
M = Manufacturer
C = Calculated

Weights listed are in ounces.

Parts in purple are amongst the lightest options


****Upper Parts****
Muzzle Devices
A2 Flash Hider       2.15 U
A2 Extended
Mag Tactical             1.90 M
BE Meyers               2.50 M
AAC Brakeout 51t   4.20 M
AAC Blackout 51t   4.30 M
VDI Manimal            1.48 M
Rainier Mini-Comp    1.44 U
ALG Single Chamber Brake 2.01 U
V7 Titanium   1.35 M
V7 Ti V-grooved  1.25 M
Venom Defense hybrid steel muzzle brake 1.48 U

Charging Handles
PSA Milspec  1.13 U
Breek Arms Warhammer 1.0 U
Spikes Milspec 1.07 U
Rainier Raptor 1.42 U
BCM Gunfighter Med   1.24 U
BCM Gunfighter Small
V7 Ultra-light charging handle  1.04 M

Bolt Carrier Groups
LMT Semi-Auto 11.14 U
Umbrella Corp Full-Auto 11.46 U
RRA Semi-Auto 11.26 U
Spikes NIB FA 11.8 U
Colt F/A BCG 11.56 U
BCM F/A BCG 11.64 U
PSA F/A BCG 11.50 U
Red X Arms Ti 7.81 M
JP LMOS Bolt Carrier 6.25 M
JP Bolt Carrier (full mass) 8.5 M
Young Man. SLC carrier   7.1 U
FN Bolt Only 1.5 U
Smith Aluminum carrier w/ key 3.7 U
PM&T Ti carrier w/ key 5.1 U
V7 Systems Ti Carrier  5.7 M
V7 Systems Ti BCG  7.9 M
DSA Low-Mass Steel BCG 9.1 M
DSA Aluminum BCG 5.2 M
OdinWorks Low Mass BCG (steel) 9.0 MU
WDR Titanium BCG  7.8 M
FosTecH LOW MASS BCG (Nickel Boron) 8.5 M

Gas Blocks
Aero precision 0.625 adjustable
BCM 0.75"  1.30 U
BCM 0.625" 1.928 U
Daniel Def LPGB 0.750        1.28 M
Daniel Def LPGB 0.625        1.92 M
V7 Systems Ti LPGB 0.750  0.74 M
V7 Systems Ti LPGB 0.625  0.71 M
2A Armament Ti 0.750   0.70 M
VLTOR 0.625" (set screw)  1.4 M
Parallax Tactical LPGB          1.47 U
SA 0.75" adjustable 1.8 U
Samson MFG lite 0.625"  0.6 U
YHM LP w/ set screws 1.43 U

Gas Tubes
Del-ton Carbine 0.63 U
Carbine Length  0.7 C
BCM Midlength 0.757 U
V7 Midlength 0.94 U
Mid Length  0.8 U
Rifle Length 0.9 U

Dust Covers
Dust Cover Assembly  0.75 U
Dust Cover Ass., V7   0.37 M
Mako Poly Dust Cover: 0.2 (discontinued?)
UBCM Dust Cover 0.506 U
BCM Dust Cover Pin 0.211 U
BCM Dust Cover Spring 0.021 U
Strike Industries Ultimate Polymer  0.3 M
Strike Industries Ultimate overmolded Polymer 0.5 M
Strike Industries Polyflex  0.3 M
Magpul Polymer   ?

Forward Assists
BCM Forward Assist 0.712 U
BCM FA Spring 0.058 U
WOA Forward Assist Assy  0.74 U
Northtech Ti Forward Assist 0.501 U
Northtech Ti FA Spring 0.050 U
Schuster Mfg FA plug  0.10 U

Upper Receivers
2A Armament Balios Lite stripped, no FA  5.8 M
Aero Precision Forged Stripped 7.16 U
Aero Precision Forged Stripped; no FA   6.4 U
Fostec FLITE Elite Stripped 5.92 M
Kaiser X-7 Poly Upper: 5.5 M
Mega Arms forged stripped 6.9 M
Mega Arms Billet Upper, 9.4 M
Rainier Forged, Complete  8.6 M
Rainier Arms Forged Stripped 7.08 U
Spikes Forged complete: 8.4 U
V7 Weapon Systems Forged Complete 7.7 M
V7 Weapon Systems Forged stripped 6.8 M
V7 Weapon Systems Enlightened 6.0 M
V7 Weapon Systems Enlightened (lithium/aluminum) 5.8 M
Forged no FA, complete  7.3 C

All the cheap gun stuff is on Ali Express now!!! I love $15 knockoff nsr hanguards! 😁

I have been trying stay off Ali and the like. As every year I did my card number was stolen.

I might get a gift card this year and make some purchases

But most sellers take PayPal, lol. They never see your credit card info!

Anyone know the lightest sling QD mlok mount?

Edit: found one. Impact weapons components. .314 ounces. 6061. V7 was a tad over .4 ounces but stronger at 7075. I feel 6061 is plenty for a QD mount though.

I’m using U Loops on my LW gun instead of QD’s

That’s a good idea too.

I was curious about weights of the Clark handguards, clamp vs glue, and saw on the PWD that the difference wasn't clear. Got this today when I asked:

I am including information from our web page that has the weights of the handguards with the barrel nut included in the weight.  The clamp itself weights 1 oz so add 1 oz to the weights listed below for the clamp on model.

Please let me know if you have any other questions.

Regards,

Specs.:

2.025″ Outside Diameter
1.88″ Inside Diameter
Backing plate and Sling Stud add 1 ounce
Weights include the barrel nut
PART # WEIGHT / LENGTH
CLK-750SBR4

3 ounces / 4″ long
CLK-750SBR6

4 ounces / 6 1/4″ long
CLK-750C (Carbine) 5 ounces / 9″ long
CLK-750 (Standard) 6 ounces / 12 5/8″ long
CLK-750L (Extra Long) 7 ounces / 16″ long

Logan Clark
President CCG Inc.

Good info, I'll have to add it to the PWD... Which is getting an update soon!

OK, we are into ultra light weight AR rifles.

So does an ultra lightweight 50 BMG count????

Shot Show most 50 BMGs weigh 40 pounds plus.

So this new rifle they are saying as 50 Black Out weighs 19 pounds, so it does qualify?

Seems they use a lot of AR15 parts in to lower, but I could see the ounces melting off the lower from our lists. Add a titanium muzzle brake and cut half a pound off the upper.

Shoots a 911 grain bullet.

One comment was his shoulder ran away and hid! Amen

Can't find any info on it. Is it a wildcat? Describe it!

John from The Gun Collective had a video of that rifle up on his you tube channel, here is the link:

Lightweight 50BMG? But HOW?!

Looks like I have a small issue with my Coda handguard now. One of the trunnion screws pulled out the threads, and now it's sitting on my desk. Waiting for their repair/warranty guy to get a hold of me to try and get this handled.

Now I have the idea to try out another handguard depending on how things go.

Well something happened on my range trip.

I guess my pics didn't actually take. It was cold last week.

No melting on the poly free float. I only put about 100 rounds through it in a time period of about 20 minutes though. (Lunch break)

I did get a lot FTF. I assume the bcg is moving too fast to get the next round. So I put the weights back in the buffer for next time.

Hope you get the FTF worked out bacon.

Loonytik did you get your issues solved yet?

Nope. I've emailed DSArms twice and haven't heard back from them. I plan to give them a call next week to see if they will RMA the bolt. The rifle works fine....with a different BCG.

Have you tried a different bolt in the DSA carrier?

No, I haven't tried that. I've swapped the BCG into a different rifle with the same results but, haven't swapped out the bolt.

It's a thought.

It's got to be the bolt!!! Probably Chinese junk 🙄 I never used the bolt it came with.

Wait....you only used the carrier and swapped out the bolt? Is there a reason why?

I'll have to try swapping the bolt with one of my other lightweights to see if that changes things. Gotta get this rifle running...too expensive to just sit in the safe.

I wanted to use a cryptic coatings mystic black dlc bolt to reduce wear on the aluminum carrier. I'm also using jp precision gas rings for the same reason.

There is most likely nothing wrong with your bolt carrier group. You NEED to understand what forces you are playing with here. Chances are your system is still over gassed. I understand you went with an RCA gas key? I have not had great success with adjustable keys and carriers as even if the key was completely closed the pressure in the gas tube still pushes the key backwards unlocking the bolt and starting the extraction cycle. Reducing gas at the gas block is the best method for ultralight actions. I added a threaded insert to my non adjustable gas block to reduce gas to my 2A regulated bcg and have seen a significant increase in adjustability and reliability.

Hope that helps.

I've had the opposite experience. I've found the adjustable keys to be more precise. Could always try the dsa bolt in your go to rifle, just swap the bolts for the next range trip!

I know you can get it to work because I’m running almost the identical setup as you. 10.5 Faxon barrel, DSA sand cut  BCG with RCA adj key, Nemo 300 BO spring and a cut down Taccom buffer.
It’s a stock DSA except I put a Ti cam pin and FP in it.

I only ran 100 rounds through it so far but not a single hiccup.

And I'm running a similar build but it's a 16" mid length and not a single hiccup!!! That's why I think it's a bad bolt. Whenever I see a nitrided bolt I kinda automatically think it's gonna be poor quality. I know that's not logical because there's kak and a few other companies making them well but I prefer dlc, chrome, or even a parkerized/phosphate bolt. Kinda sucks that you're not getting any response from DSA customer service. I really like their stuff!!! I expected better of them.

I might consider this IF I hadn't swapped this same BCG into two other rifles that I know cycle anything I throw at them. I had the exact same issues. I also swapped the BCG's from those rifles into my lightweight rifle and it cycled everything, no issues.

I just swapped out the bolt in the DSA carrier with one from a Toolcraft BCG. I'll see what happens at the range this weekend.

Hey guys, have a question about 2nd amendment armament. I ordered there titanium adjustable carrier back on Black Friday and still haven't received a shipping notice. I've contacted them twice and they said they were working on filling back orders and should be done by the end of the week or the beginning of next week. That was back on Jan 27.
I have patients to wait for a quality part just wish they would tell me the truth about the wait time.

So my question is this what kind of wait time have you guys had with them?

Here is a pic of the build I'm working on. 12" 6.5 Grendel



I'm not trying for an ultra lite build but trying to keep the weight down as much as possible. I have everything but the carrier at this point and I'm sitting at 4.85lbs.

Was surprised at how heavy the Gibbs upper was but I think I'm going to like it .

After I get my final piece, its off to get cerakoted

Thanks guys

That's a crazy of a long wait in my opinion!  I have never used them so cant help you there.  I do know I would have moved on by now and spent the cash elsewhere but I'm not real patient any more! (OLD)
Liking the build you got there! Show us when its all finished up please!

I waited 16 weeks on their Palouse receiver sets.

I guess we'll wait and see

@Loonytik that really sucks, but I really like this carrier so I guess I'm in for the wait.

https://www.2a-arms.com/product-p/ar15tirbc.htm

Finally...SUCCESS!

I swapped the bolt from a Toolcraft into the DSArms carrier and NOW I have a functioning rifle! I put 150 rounds through it with no issue with the brass ejecting at 2 O'clock 90% of the time. I did have 3 failure to ejects between 150 and 200 rounds but, I figured out that I hadn't put the set screw on the RCA adjustable key and the inner screw was basically allowing all gas through. Solved that and ran it several more rounds with no issues.

Thanks for all the suggestions/help!

@pscot468
@larrys
@breastroker
@jekbrown

and others.

Awesome Loonytik! So glad you got that baby running.

Finally!!! That bolt must have been cheap Chinese junk!!!! Crazy... Don't forget to use your 5 coil extractor spring/o-ring/insert in the new bolt ;) stuck cases in the chamber aren't your friend!!!

Just updated my build with some lighter parts (V7 Castle Nut and Ultralight Pins, Smokes end plate, and Elftmann push button safety), and a new optic in the form of the Bushnell Lil P. Need to weigh it, but I should be under 4.8lbs without a mag.

4.05 lbs - rifle
4.88 lbs - rifle with suppressor and red dot (not the acog thats in one pic)
it's been a while since I worked on this gun, might be about time to cut another 1/4 lb

Forgive me for not searching all 117 pages.  I referred to the first page for most parts, but settled on several other parts that are similar or better in weight that weren't even listed.  I'm now looking for info on optic choices.  I was really interested in the Leupy Mark AR 1-4 at 9.6oz but now I see it is discontinued.  So far I have a 4.2lb AR needing an optic.  Is there a compiled list of weighed red dots, fixed powers, lpvo's etc that I havent seen yet?

https://docs.google.com/spreadsheets/d/1I6Qb6kAJjChEJ56qhznv2291c5UHRDyNXuSXGObumqM/edit?pli=1#gid=1426264395

This spreadsheet is what you want.

Perfect.  Wish I'd seen that before I started my build!

make 2 builds then 😁

Thank you to everyone involved with the spreadsheet. It's invaluable.

This isn't 5.56 so it's technically outside the purview of the project, but I thought this would be a good place to ask:
What's the lightest (and ideally modular, but willing to compromise) .40 or .45 caliber suppressor out there that's also capable of handling subsonic .300 BLK/9x39 loads? I was thinking of ordering Krebs' 9x39 pistol somewhere down the line, and I'd like to get the lightest suppressor I can find that will also work on my .40 caliber pistols.

Just an update: I received my carrier from 2a armament yesterday and looks real nice. Can't wait to get this out to the range  but its off to get cerakoted next. Build weight is up to 5.11lbs now.

Took the light rifle out for another spin this weekend with good success. Now that the bolt from the DSArms BCG was replaced I haven't had any issues with cycling. The only issue I have now is getting the bolt to push another round in when it's locked back. The spring and carrier don't have enough force to fully seat the new mag round. I usually end up removing the magazine and giving the charging handle another pull back. I used both PMAG's and Lancer mags. Any suggestions there?

Which DSA BCG did you get? I just ordered the aluminum sand cutter. Should I be worried?

More gas or a heavier buffer.  I'd try more gas 1st.

So your issue is getting the first round of a fully loaded pmag or lancer to chamber when your gun is locked open and you press the bolt catch? I think this is common with lancers, even with mil spec carbine springs. I use DD mags, I don't have this problem. It's just your weak Nemo 300 blk subsonic spring, not really sure if there's a good fix other than different magazines. One of the prices you pay for softer recoil!!!

He's got the sand cut aluminum too. The included bolt was cheap Chinese garbage, couldn't get the rifle running until he swapped it for a good bolt. I also use the dsa aluminum sand cut carrier but I never used the bolt that came with it. The carrier itself is g2g.

Not a gas issue, cycles fine.

That's right. The bolt doesn't fully seat against the barrel when I hit the bolt catch. I figured the spring was the issue but, I didn't have another to switch it out with on that trip.

Thanks.

CDNN has Bushmaster fiberlite clone stocks for $9

Good deal right there!!! Might work on my $2 polymer buffer tubes, lol.

I had the same issue with my lightweight build before. Switched the mil-spec buffer spring with a Tubb's flat wire buffer spring and the problem was gone. From my research, Tubb's flat wire AR-15 buffer spring has more power with bolt open which aids in chambering the first round.