AR Lightweight Budget Build Challenge: See my results!

[zackmars]

Don't forget to grab an RMR to mount on top of the ACOG. And don't sully the ACOG by putting a Holosun on top of it.

Quality deserves quality. I got very annoyed at companies with good reps using YFS screws in everything. I really dont want to break out a Dremel on a 1k optic and a $100 mount because they cheaped out on screws


"American" defense manufacturing my ass

 

[TEXAS "All or nothing"]

So earlier this week I had a spare receiver, LPK, and I felt like doing a "challenge" build throughout the week. I wanted to build a complete 16" AR-15, with an LPVO+mount, that weighed 7 pounds or LESS all inclusive (bolt, lower, upper, stock, optic + mount) for under $1000.

The lightest budget friendly AR I could find on the market was the M&P 15. It's a standard setup featuring an adjustable stock, and colt-style handguard. It weighs in at 6.7 pounds per the manufacturer website. That's without optic or mount, just iron sights. MSRP is $812 per S&W's website. Here's that rifle below.


Additional criteria:
- No skeletonized parts (bolt, handguard, stock, grip, etc). I'm sure I could have shaved another half pound off by skeletonizing everything but that would have increased cost by a LOT going over my budget, and also I am not a fan of running things like a skeletonized bolt, or handguard. Sorry, just my preference, I don't trust the durability. Been to too many carbine classes where someone was out of the game after an hour because their skeletonized handguard cracked under normal course usage.
- No pencil barrels. This could have saved me another 7-9 ounces of weight probably, but again, I am not a fan of pencil barrels due to your POI shifting greatly after moderate use (several MOA from my experience after 2 mags).
- No super short or non-MLOK handguards . I'm a tall guy, and I like to have a longer handguard to get a proper c-clamp grip. So can't do short handguards. I also prefer MLOK due to the vast amount of accessories.

If I had used skeletonized parts, short handguard (below 12"), and a pencil barrel, I am sure I could have gotten under 6 pounds with optic (probably 5.5 - 5.8 area). But probably would have spent another $500+ easily. But I digress.

My build details below. With each part I weighed them separately on my compact kitchen scale, and tried to round off to the closest hundredths of an ounce.

1. Completed Lower - Magpul Fixed MOE stock ($30/9.5 ounces), PSA stripped lower ($50, 8.8 ounces), CMMG AR15 LPK w/o FCG ($15, 1.25 ounces), Fostech Binary Sport Trigger ($260/3.6 ounces), Milspec pistrol grip w/hardware ($5, 2.5 ounces), Guntec Carbine buffer kit with tube, carbine spring, and carbine buffer ($29.99, 6.5 ounces).
   Total Lower weight/costs: $390 / 32.15 ounces or 2.0 pounds
   
   
2. Completed Upper - United Defense BCG FA profile ($60, 9.2 ounces), APF Armory 5.56 NATO 16" barrel 1/7 twist ($240, 27 ounces), Davidson Defense 15" Slim profile MLOK handguard with barrel nut ($50, 15 ounces), Recoil Technologies Micro Low-Profile gas block kit with tube ($18, 3.4 ounces), Strike Industries LINK handstop ($12, 1.4 ounces). Various pins + dust cover ($5, 1.0 ounces). I got a free ambi-charging handle from Delta Tactical for ordering the BCG and handguard in the same order, but I'll add $10 and 2 ounces for that as well to make it more realistic.
   Total Upper weight/costs: $395/ 59.0oz or 3.68 pounds
   
   
3. Optic setup - Vortex Crossfire ll 1-4x24 LPVO ($160, 14.8 ounces), UTG 30mm Quick Detach Rings ($29, 2.4 ounces)
   Total Optic Setup weight/costs: $189 / 17.2oz or 1.08 pounds
   
   

   Rifle total Weight/Costs: $974.00 / 108.35 ounces or 6.77 pounds​

Now just to sanity check myself, I weighed the complete rifle on my scale with a single empty magazine inserted. I got almost 7 pounds on the dot. Seeing as your average 30 round plastic mag weighs around 3-3.5 ounces, I'd say the total weight was well within the margin of accuracy you can expect from a kitchen scale.
View attachment 348316

Complete rifle:
View attachment 348317

It's so light, I can actually swing it like a baseball bat when I run dry.

Not bad weight for what you did on just lying around parts. A little more costly here on this build. ATI poly receivers (under $30 each), faxon pencil barrel, CF buttstock and handguard. 4# 7.05oz dry. 5# 1.2oz as pictured. Holds under 1.5moa with m855 after 360 rounds just over 4 minutes. Works for me.

 

[Big Green]

I have never understood the desire for an extremely light weight weapon. While I have seen a very few well done ones that were extremely expensive, it seems like the only goal was light weight and an exercise in spending money.

I’d rather have an 18” barrel to keep velocity higher for M855, a good rail and a solid optic, at minimum an ACOG. My “RECCE” build has an 18” FN CHF barrel with gov profile, lighter Geissele rail and Trijicon 4-12.5. Not much difference in weight compared to my issued M16A2 or M16A4.

If I really want light weight I’ll grab an AR pistol or my AR in SBR form.

I’ll take a heavier MK12 styled weapon any day, IMHO. You kick in the door, I’ll provide cover. Todd will probably take M4 or MK18.

 

[toddnjoyce]

…Todd will probably take M4 or MK18.

Most of us would be better off just being lighter weight.

 

[Sasquatch]

I have never understood the desire for an extremely light weight weapon. While I have seen a very few well done ones that were extremely expensive, it seems like the only goal was light weight and an exercise in spending money.

I’d rather have an 18” barrel to keep velocity higher for M855, a good rail and a solid optic, at minimum an ACOG. My “RECCE” build has an 18” FN CHF barrel with gov profile, lighter Geissele rail and Trijicon 4-12.5. Not much difference in weight compared to my issued M16A2 or M16A4.

If I really want light weight I’ll grab an AR pistol or my AR in SBR form.

I’ll take a heavier MK12 styled weapon any day, IMHO. You kick in the door, I’ll provide cover. Todd will probably take M4 or MK18.

There is one scenario where a light rifle makes some sense from a practical standpoint - that is hike-in hunting. If you're hiking into an area for a good distance, or you're doing a lot of scouting - having a light weight rifle is real nice over a heavy gun.

You're trading off increased recoil though, and maybe a tad less stability depending on the weight balance (not an issue if yo'ure shooting off sticks / bipod / supported, but can be if you're shooting off hand and your gun is real wiggly because it weighs nothing, and you're all jacked up because you spent 8 hours scouting and stalking and finally saw something legal to shoot)

Otherwise - ultralight rifles are just neat toys. "Because I can" is a totally valid excuse to do anything (legal anyway) but practicality sometimes necessitates other decisions.

 

[Axxe55]

I just don't understand the fascination with ultralight rifles just doesn't make sense it's been hundreds to save a few Oz

 

[toddnjoyce]

There is one scenario where a light rifle makes some sense from a practical standpoint - that is hike-in hunting. ….

This really proves my point. Lose 10 lbs getting in shape to hike in a mile or two or spend hundreds to shave ounces.

Yes, some people log long mileage days all season long. They’re a small minority of use cases.

 

[Lonesome Dove]

Just watched a big guy get out of this.

 

[Sasquatch]

Just watched a big guy get out of this. View attachment 348567

Was he wearing pink matching crocs?

 

[Maverick44]

I just don't understand the fascination with ultralight rifles just doesn't make sense it's been hundreds to save a few Oz

Ultralights are a whole different game from just lightweight rifles. With those, I think it's mainly just a game to see how light you can make the gun and it still work. That's not a game I'm too interested in, but to each their own. One factory AR comes in at 4.6lb with a 16" barrel. Yes, it's stupidly expensive.

BATTLEARMS™ OIP® 003 Ultra Lightweight Rifle Gen 3

MODEL OIP, BILLET 7075-T6, SEMI-AUTO, 16" .223 WYLDE, 4150CM BLACK NITRIDE BARREL , 1:8T, FIXED STOCK, TI & CARBON FIBER COMPONENTS, OPTICS READY, ULTRALIGHT , COMBAT GRAY (1) 30rd MAGAZINE

www.battlearmsdevelopment.com

With lightweight AR's, there's a practicality there, and it's not that hard to keep the gun light. Mainly, just don't pile a bunch of chit on it. The KISS rule is king there. Sasquatch picked out parts for one for less than $1k earlier in this thread. 7 lb with an optic is pretty good target to shoot for.

 

[glenbo]

Looks and sounds great to me.

 

[Axxe55]

Ultralights are a whole different game from just lightweight rifles. With those, I think it's mainly just a game to see how light you can make the gun and it still work. That's not a game I'm too interested in, but to each their own. One factory AR comes in at 4.6lb with a 16" barrel. Yes, it's stupidly expensive.

BATTLEARMS™ OIP® 003 Ultra Lightweight Rifle Gen 3

MODEL OIP, BILLET 7075-T6, SEMI-AUTO, 16" .223 WYLDE, 4150CM BLACK NITRIDE BARREL , 1:8T, FIXED STOCK, TI & CARBON FIBER COMPONENTS, OPTICS READY, ULTRALIGHT , COMBAT GRAY (1) 30rd MAGAZINE

www.battlearmsdevelopment.com

With lightweight AR's, there's a practicality there, and it's not that hard to keep the gun light. Mainly, just don't pile a bunch of chit on it. The KISS rule is king there. Sasquatch picked out parts for one for less than $1k earlier in this thread. 7 lb with an optic is pretty good target to shoot for.

my AR weighs a hair over 6 lb and I'm happy with it

 

[CaliGunner]

Good luck. It's one thing if something is obviously bad out of the box, but it really sucks when the thing goes tits up in a class.

Huh. Optic seems off a few inches. NBD, aaannd the windage has no clicks... And the elevation is seized up. And there goes the entire brightness knob...

Vortex sent me a new one, windage was seized up, as was the eye piece. Third one the magnification ring would easily spin and wouldn't adjust the magnification (stuck somewhere around 2.5-3x)

Going to pre-empt your next thread; get a trijicon ACOG.

Yeah, if it survives this next carbine course, I’ll give it a pass, and I haven’t had an optic failure in a course going back to 2011. My initial function test was perfect. I even added a throw lever on the mag ring, and it was really smooth back and forth.

Regardless, 8 hours of close and mid-range shooting drills with emphasis on shooting positions, operation and combat marksmanship. Should be a great test.

Just in case, I’ll bring this as a backup.

 

[CaliGunner]

Not bad weight for what you did on just lying around parts. A little more costly here on this build. ATI poly receivers (under $30 each), faxon pencil barrel, CF buttstock and handguard. 4# 7.05oz dry. 5# 1.2oz as pictured. Holds under 1.5moa with m855 after 360 rounds just over 4 minutes. Works for me. View attachment 348447

Love it! How are you liking the poly receiver? That’s gotta be under 5-6 ounces right? Any issues?

My next goal is to do a 6 and under build, rifle + optic. I’ll definitely have to spend a bit more.

 

[Lonesome Dove]

Was he wearing pink matching crocs?

Couldn't stare that long to notice. I had food in my mouth.

 

[CaliGunner]

I have never understood the desire for an extremely light weight weapon. While I have seen a very few well done ones that were extremely expensive, it seems like the only goal was light weight and an exercise in spending money.

I’d rather have an 18” barrel to keep velocity higher for M855, a good rail and a solid optic, at minimum an ACOG. My “RECCE” build has an 18” FN CHF barrel with gov profile, lighter Geissele rail and Trijicon 4-12.5. Not much difference in weight compared to my issued M16A2 or M16A4.

If I really want light weight I’ll grab an AR pistol or my AR in SBR form.

I’ll take a heavier MK12 styled weapon any day, IMHO. You kick in the door, I’ll provide cover. Todd will probably take M4 or MK18.

Do a 2 day carbine/rifle course, I’m being serious here.

I’ve seen in-shape (like 12-15% body fat) former active duty audibly comment about their discomfort on having a heavier rifle during classes. These guys aren’t your average overweight 50+ year old indoor range weekend warrior. A lot of them still work private security or law enforcement.

On the 100th drill, your 14.5” Noveske Afghan, ACOG up top, UBR stock, 9.5 pounds with full magazine starts to feel much heavier than it really is.

 

[toddnjoyce]

Heh. This is gonna get real interesting.

 

[Sasquatch]

Heh. This is gonna get real interesting.

I don't think he knows what Big Green does. Not that his user name is a clue, or somethin'.

 

[Fishkiller]

I don’t know what to say. Never been in military but pick up a m1 or BAR from WW2. You want weight they provide it
If I was gonna take a tactical rifle training class I want the rifle I go out for defending me. But to each his own

 

[Maverick44]

Love it! How are you liking the poly receiver? That’s gotta be under 5-6 ounces right? Any issues?

My next goal is to do a 6 and under build, rifle + optic. I’ll definitely have to spend a bit more.

You might want to look into the WWSD 2020 rifle project and see what they did to make the gun light then. It comes in at 4.97lbs without a mag or sights. Put a lighter weight sight on it, and it should be under that 6lb mark, and will be a very practical gun. The purpose of the gun was to make a fully modernized/improved version of the AR based on what Stoner originally wanted out of the gun. It's purpose wasn't just to be light, though that was a very important part of the design.

A complete one is not cheap ($1500), but you can get all the individual parts and build one cheaper with some alternatives.

Semi-Auto | Rifles at Brownells

Brownells is your source for Semi-Auto,Rifles at Brownells parts and accessories. Shop our vast selection and save!

www.brownells.com

They do make a budget version of it. I don't know anything about it. $1250, 5.11 lb

CIVIL DEFENSE RIFLE (CDR) RIFLE | Brownells

The Civil Defense Rifle (CDR) is a joint development between KE Arms & InRangeTV. With a similar thought process to the fully featured WWSD2020, the CDR is a lightweight, modern carbine, ready out of the box for hard use. The heart of the CDR is t...

www.brownells.com

Here's how you make it cheaper, though these changes takes away what makes it a WWSD, and turns it into just a lightweight rifle. I'm assuming that's all you care about. It'll be a good rifle regardless.

Replace the KE Arms SLT-1 trigger with either a standard milspec trigger, or a LaRue MBT (highly recommended)

Replace the JP Silent Capture Spring System with a standard buffer and spring.

Switch the ambi controls for standard controls.

Switch the Geissele Super Charging Handle for a standard on, or an improved one like the BCM Gunfighter.

Use a standard BCG instead of the fancy chromed one.

Here's the build.

KE Arms KP-15 Lower. This is your lower, stock, grip, trigger guard, and buffer tube all in one. It uses a carbine buffer and spring. $81.99, 27.2 oz

AR-15 KP-15 STRIPPED LOWER RECEIVERS POLYMER | Brownells

What makes this stripped lower different? The answer is simple… the KE Arms KP-15 stripped lower receiver is a monolithic polymer AR-15 style lower receiver made from injection molded, 30% glass-filled nylon. Its unique design incorporates the buf...

www.brownells.com

Buffer spring and carbine buffer. Take your pick, around $15 and around 5 oz

LPK, again take your pick. About $65 and about 4 oz

Aero assembled upper $79.99, 8.3 oz Their slick sided upper is 6.5oz.

https://www.primaryarms.com/aero-precision-assembled-ar-15-upper-receiver-with-port-door-and-forward-assist-ap501603-asmbly?quantity=1&custcol_pco=Orphan

Strike Industries ARCH charging handle. (You can go cheaper). $39.95, 1.12 oz

Strike Industries ARCH AR-15 Charging Handle - Extended Latch - Black

DetailsThe Strike Industries Charging Handle is machined from a 7075-T6 aluminum forging then hardcoat anodized black for long term wear and corrosion resistance. This AR-15 charging handle features an enlarged latch that allows you to more easily manipulate your rifle from the side. Even when...

www.primaryarms.com

Flash hider, take your pick. $7 and about 1.9 oz

Ballistic Advantage barrel, 16" pencil with a pinned gas block, BCG, and gas tube. $354.99, 23 oz for the barrel, about 15.5oz for the rest. The Faxon version is about 4 oz lighter.

16

Our 5.56 NATO barrels are made by experts with extreme attention to detail. You can trust this 16 inch pencil profile AR 15 to exceed your expectations.

www.ballisticadvantage.com

Faxon 13" carbon fiber handguard. $339.00, 7.99 oz. (there's also a 15" version)

Faxon Streamline Carbon Fiber 13" M-LOK Handguard

Faxon Streamline Carbon Fiber 13" M-LOK Handguard | Rifles, Pistols, Rifle barrels, AR-15 parts, Pistol Parts | faxonfirearms.com

faxonfirearms.com

Total cost - $982.92

Total weight - 94.01 oz or 5.87 lb. Switch to a Faxon barrel and an Aero slick sided upper receiver, and that weight will be closer to 5.51lb

Keep in mind, there's some educated guessing going on here with the weights, and I'm not sure I fully trust what the manufacturer says. I don't know if they're rounding their number up or down.