Lightweight lowers - small and large frame

[sam4886]

Welp, with Washington constantly trying to ban these evil assault weapons, I'm shopping again.

I've got a couple things waiting to be built right now, but I'd like to get a nice lightweight lower in both small and large frame. I don't want polymer.

I've done some searching and found the normal mentioned suspects like v7, BAD and 2A.

Does anyone have any experience or suggestions on lighter lowers? They all seem expensive, but I'd like this to be as economical as possible.

 

[Stavey]

Very simple
Go to 80%arm.com
Buy a lower or 2 and a jig
Make said lowers
Sell jig to recoup some of the measly $130
Enjoy your freedom

 

[MPDS13]

I recently had 2 rifles built using the San Tan Tactical Lightweight receiver set. They look awesome and are really light for what you are getting. Not completely sure the weight difference them and V7. I know V7 makes some awesome lightweight stuff.

 

[sam4886]

I've done a few 80%ers. No worries there.

I'll look into San tan.

I'm starting to think the receivers aren't the best place to lose weight anyway. An aero m4e1 is 8.6 oz, the BAD and 2A are about 6.7, depending. Doesn't really see like an economical place to trim, but then again, oz make lbs....

 

[TonyTheTiger]

I'm starting to think the receivers aren't the best place to lose weight anyway. An aero m4e1 is 8.6 oz, the BAD and 2A are about 6.7, depending. Doesn't really see like an economical place to trim, but then again, oz make lbs....

That was my first thought when I saw the thread title. Barrel, stock and HG, probably in that order, are the easiest places to cut weight. But if you're really trying to get light V7 and 2A have happy customers. Don't know anything about these but the weight is impressive: https://www.masterofarms.com/index.php?main_page=product_info&cPath=1&products_id=66

 

[srt-4_uk]

For the AR10, the small frame guns are pretty damn light weight

SF10 Small Frame AR10 - Proof Research Model (308 & 6.5) - F4 Defense

Common Use: LE/Military, Hunting, Competition, and Precision Long Distance Shooting. The SF-10 is a DPMS® GEN II compatible Small Frame AR10. The SF-10 is a compact, lighter, and more dynamic version of the AR10. Lead times are typically 8-10 weeks, please call (240-808-2314) or email...

www.f4defense.com

 

[sam4886]

Definitely nice to see options. They all look to weigh about the same and run about $250.... Guess it comes down to looks.

 

[hlee]

Your steel parts are where you save weight, or large parts. Pencil barrel. low mass carrier. Avoid the magpul PRS stock. Carbon fiber hand guard.

 

[smcfarland]

Built mine with an F1. Have been happy with it. Buddy did a similar build with 2A and has been happy with it as well.

 

[Yondering]

I've done a few 80%ers. No worries there.

I'll look into San tan.

I'm starting to think the receivers aren't the best place to lose weight anyway. An aero m4e1 is 8.6 oz, the BAD and 2A are about 6.7, depending. Doesn't really see like an economical place to trim, but then again, oz make lbs....

You won't lose a lot of weight with the specialty lightweight stuff, compared to a typical forged lower. I've done some extensive machining on some lowers to reduce weight, and didn't end up losing that much in the end.

However, you can gain a good bit more with some of the billet lowers if you don't pay attention to weight. My MO these days is to just use a decent forged lower, and focus on barrel, handguard, and stock for weight, in that order.

 

[Dolomite_Supafly]

I am currently building a lightweight rifle. I have been weighing everything.

I am currently at 5 pounds 11 ounces with a Vortex Sparc.

I use a forged upper without a forward assist or port door. Magpul pistol grip on a standard lower. I used a Shockwave brace, not because it is a pistol but because it is lightweight at 7.4 ounces.

A rifle length buffer tube is lighter than an adjustable carbine tube. I am going to make a minimalistic buttpad that bolts to it.

The BCG is a lightweight Brownells unit.

The barrel is a super lightweight 16” pencil with a rifle length gas system. It has a 223 “match” chamber. It is .65” at the chamber then tapers to .55” at the .625” gas block. I shortened the gas block pad to match the block then turned the barrel ahead of it to .5”. It is very accurate with no heat related drift.

I found a cheap handguard that actually ended up being lighter than anything else I could find.

I use a standard carbine buffet but removed the weights and replaced them with powdered copper so it acts like a dead blow hammer. It now weighs 1.1 ounces and I have had zero malfunctions in the 300+ rounds fired so far. I even weighed the recoil springs to select the lightest one.

Right now I am searching for a lightweight red dot that is lighter than the Sparc. I have a few Fast Fires but the dots are not clear to my eyes.

 

[LeadZeke]

When it comes to lightweight, there is no question for the small frame: V7 Weapon Systems lithium alloy 2055 is head and shoulders above the rest. It is not only lighter but stronger and more rigid. Not a huge deal for a lower but it does help for a lifetime purchase. For the upper it is really critical for accuracy.

For the AR10 it is more complicated. V7 hasn't released their lithium alloy set for it yet. So it is all 7075 competition, and the 2a Xanthos is as light as it gets, but some claim it also deflects more. Again, upper problems but if you are buying the lower you might as well get the upper in either case. I'd recommend either.

Ounces make pounds, and pounds make pain. If you focus on getting quality lightweight parts from places like V7 and 2a you can build rifles 2-4lbs lighter than others with the same levels of reliability and durability (just an increase in cost).

Also keep in mind if you also want to do an 80%, you cannot buy it with a credit card or anything link to your name, or ship it to your house. Use pre-paid cards or cash and ship it to an LGS or somewhere else. Otherwise you gain nothing from the 80% because all of that is tracked.

 

[Yondering]

I am currently building a lightweight rifle. I have been weighing everything.

I am currently at 5 pounds 11 ounces with a Vortex Sparc.

I use a forged upper without a forward assist or port door. Magpul pistol grip on a standard lower. I used a Shockwave brace, not because it is a pistol but because it is lightweight at 7.4 ounces.

A rifle length buffer tube is lighter than an adjustable carbine tube. I am going to make a minimalistic buttpad that bolts to it.

The BCG is a lightweight Brownells unit.

The barrel is a super lightweight 16” pencil with a rifle length gas system. It has a 223 “match” chamber. It is .65” at the chamber then tapers to .55” at the .625” gas block. I shortened the gas block pad to match the block then turned the barrel ahead of it to .5”. It is very accurate with no heat related drift.

I found a cheap handguard that actually ended up being lighter than anything else I could find.

I use a standard carbine buffet but removed the weights and replaced them with powdered copper so it acts like a dead blow hammer. It now weighs 1.1 ounces and I have had zero malfunctions in the 300+ rounds fired so far. I even weighed the recoil springs to select the lightest one.

Right now I am searching for a lightweight red dot that is lighter than the Sparc. I have a few Fast Fires but the dots are not clear to my eyes.

5 lb 11 oz is not terribly light; quite a few basic carbine setups weigh in right about 6.0 lb to start with. It kinda sounds like you're focusing on light weight in some of the wrong places - like buffer weights.

You can save a lot of weight off of that stock/brace setup by using a Smoke Composites stock; the entire thing weighs about the same as a buffer tube alone.

Handguards and barrel nuts are another big one. If you want to go light, an aluminum barrel nut with a thin carbon fiber tube attached for a handguard can be lighter than most steel barrel nuts by themselves.

 

[ActualCryptid]

I built an ultralite AR (4.5lb with a RMR) using the 2A Palouse upper and lower. Real high quality, worked well with the Ti pins, but the one issue I had was the magazine release hole was too tight for the magazine release button. A little jeweler's rouge and some time solved it, but might be worth checking on.