Aero Precision’s Skeletonized AR Lower

Looking to build the lightest AR-15 possible? Well this might be right up your alley. Aero Precision posted  a picture of their skeletonized AR-15 lower on their Facebook page to see how much interest there was in such a lower. It’s machined from 7075-T6 forged aluminum and will work with all standard AR magazines and components. How light is it? According to Aero Precision their skeletonized lower is just .357lbs vs .526lbs for their standard lower, a 32% reduction in weight. According to this Aero Precision product page they may retail for $150 if they actually make them. Aero Precision even posted a video of their prototype lower showing it functioning after being covered in gravel. Thoughts?


Ray I.

Long time gun enthusiast, archery noob, Mazda fan, Sci-Fi nerd, Whiskey drinker, online marketer and blogger. My daily firearms musings can be found over at my gun blog and Instagram.

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  • I would take this lower any day over a poly lower. Looks like they have just removed the extra material in the solid areas. From what I am reading locally (Aero is local to me) they are very strong and very well made lowers.

    • I have three of them. Will recommend the lowers any day.

    • Esh325

      What exactly happens when say this receiver experiences a catastrophic failure?

      • Generally speaking the lower on an AR15 isn’t AS critical during a failure as the upper is. Having seen hundreds of photos and several first hand failures, I have yet to see anything rear of the magwell that is destroyed in an explosive manner. I have seen bent, cracked and things of that nature though. Obviously the upper, BCG and barrel take most of the damage, with the magwell taking damage and generally ejecting the magazine out to the magwell in the process. I have also seen failure of the buffer collar, but seeing as this lower is metal and the collar is solid metal I would expect the same type of failure I have seen in other metal lowers. With that, a catastrophic failure that caused a failure in say a polymer, or reinforced lower could become polymer shrapnel as the collar expands and fails, breaking the polymer off the reinforcement insert.

        While there would be the possibility of a failure causing the lower to fly apart I would imagine the lower being skeletonized would be less apt to contain parts in the event of a failure yes, but based on how the AR15/M16/M4 platform was designed to fail, I wouldn’t be as concerned with this lower.

        • BryanS

          What about a critical failure that jams up the disconnector and turns this thing FA?

  • ThomasD

    Mag well is ok, but not sure I like the idea of an exposed fire control group. Maybe fill the gaps with epoxy resin?

    • iksnilol

      Was just about to suggest that.

    • John

      MAC demonstrated that the AR-15 is a sealed weapon system, and dirt in the FCG is a big no-no

      • jcitizen

        I had an AR-7 .22 cal rifle which was made of aluminum, that ran better with lots of dirt and carbon fouling in it, than with oil!! I could hunt rabbits all day long that way! I would occasionally clean the bolt face and extractor, but if I tried anything else it would not work. I eventually couldn’t stand it any longer, and would clean them squeaky clean and then use some magical silicone fluid( I don’t remember the product but it was recommended for the AR platform in the mid seventies, and looked more like mineral spirit with graphite in it! That stuff would keep it running long enough to get it dirty with grime and carbon, and kept it running fine until then.

  • guest

    This, plus some other “skeletonizing”, alu brass and Eugene’s original idea of a steel-lined alu barrel and this may just be the theoretical foundation for the world’s lightest carbine in that calibre.

  • John Dalton

    I will wait for the first few thousand to be tried and tested. I would never buy a first run gun design. Being able to see the FCG kind of makes me uneasy. I want as few failure options as possible and it looks like you could jam the weapon in a lot ways.


    where can we buy one as it’s not on their site?

  • Lance

    Ok this is just getting stupid. If yu want a light weight weapon get a original XM-177E2 weapons don’t buy ridicules ideas and breakable one like this.

  • Alex

    Weight reduction compared to another stripped lower is irrelevant. You’re not gonna be packin’ with just an empty lower. Only compare full rifle weight differences. This is biased.

    • Cymond

      The weight difference between two lowers IS the weight difference between complete rifles, ceteris paribus.

      Or to put it another way, if you use all of the same parts and the only difference is the lower, then the weight difference between the lowers is the weight difference between the rifles. It would be easy to build 2 rifles with slightly different specs which would distort the difference between the receivers.
      I’ve seen polymer lowers try to claim that they’re 9 ounces lighter than an aluminum lower. However, that’s more than an aluminum receiver weighs, which proves that there is MORE going on in that lower than just a polymer receiver. For example, maybe they’re comparing it to an aluminum lower with a H2 buffer or maybe they’re comparing it to an aluminum receiver with an A2 stock. In the case of New Frontier Armory, part of that claimed 9 ounce weight savings is the polymer lower parts kit including the magazine catch, magazine release button, front & rear takedown pins, and the entire fire control group. if you install a normal LPK in a New Frontier receiver, the weight difference is small compared to an aluminum lower.

  • Cymond

    I like the idea overall and I’d certainly be tempted to buy one of these. The exposed FCG makes me uneasy because it would let more dust/dirt/grime in to the gun, but on the other hand, it would be even easier to clean it out. You could just swab it out without even breaking the rifle open or you could just spray it with cans of pressurized solvents and oils.

    “Esh325” expressed concern over a catastrophic failure. Since those failures are mostly contained in the upper, I’m not sure the skeletonized lower would be a problem. To play devil’s advocate, the skeletonized lower might actually allow the pressure from a catastrophic failure to blow out of the receiver with less damage than usual.

  • Geoff a well known Skeptic

    I suspect the market for such a training aid is very limited.
    Who would have liked one as a training aid in 1972 at Aberdeen.

  • C-90

    Uh, Buried it in GRAVEL.. now dunk it in mid-east dust, Italian winter mud, and Georgia red clay spoil pile from a fighting position. Regular M-16/M-4’s in the ‘stans need cleaning after every time they’re back on base. Good as a training aid in rifle operation and maint. but not as a field weapon. And being Tacti-cool on a range in $400 Italian Camo.

    • Overthetop

      I don’t think field use is the application this is made for. 3 gun and other competition style applications is probably more appropriate. This is more akin to a race gun, than a battle rifle.

      • JumpIf NotZero

        You can’t just make something stupid and then say, it’s OK – RACEGUN!

        It saves 2.7oz from the center of the mass. It’s literally unnoticeable to anyone that picks up or shoots the gun. Yet, obviously flaws in long term durability and short term function.

        Stupid product is Stupid.

        • Overthetop

          Stupid is a relative term. knock off 2.7oz here, knock off 3oz with lighter irons, 2.3oz from a lighter handguard, and all of the sudden you are half a pound lighter. It’s cumulative.

          How one defines flaws really depends on the application. For example, a RACEGUN has obvious flaws for a carry gun. In fact, carrying one is “stupid”. However, in a competition setting, raceguns work great and aren’t “stupid”.

          • JumpIf NotZero

            No, stupid is stupid.

            Opening the fire control to debris that can stop the gun from working – IS STUPID. Weakening a part for no reason other than “looks cool” IS STUPID. Making these trade offs for the effect of saving 2.7oz in the middle of gun where it is the least noticeable IS STUPID.

            It’s not cumulative when you comprise the design. You can get a LIGHTER part using a polymer or magnesium lower and it has none of the down sides that this has. The word STUPID was chosen carefully.

          • Overthetop

            Well, thank you for your subjective opinion. Clearly this product is not for you.

  • gunslinger

    i will agree with others about dirt/grime in the FCG. any other tests with mud, water, dirt, sand..etc?

  • AR Man

    Pretty cool IMO. People collect AR lowers/ARs just because. This is conversation piece that is unique. Not for fighting, just for conversation.

  • BoHeck

    So they are the same weight and price as the magnesium lowers by Mag Tactical which look like regular lowers and have no pitfalls of skeletonization….don’t see the advantage.

    • JS

      I was thinking the same thing. The Mag Tactical lowers do require a proprietary pin that is a little longer than the standard pin, but that seems like a small price to pay for having the internals sealed from the elements.

  • Michael R. Zupcak

    While I agree with Sam Cadle that it’s better than polymer, is saving weight really worth subjecting your fire control group to anything and everything small enough to fit through those cutouts?

  • tts

    Put a very thin + light plastic cover over the cut outs to keep the dirt out and this could be a pretty cool range toy for ~$150!

    • Phil Hsueh

      That’s exactly what I was thinking, you still keep it lightweight while keeping the dirt & grime out.

    • JumpIf NotZero

      I have to ask…. Given the option of a real-deal, evolved and tested/proven…. OR…. A Range Toy…. Why would anyone “want” the dedicated toy?

      All for saving 2.7oz? WTF?

      • tts

        So long as its not too expensive then a range toy, and the range is after all where most do nearly all their shooting, is nice to have.

        • JumpIf NotZero

          I’ll just reply with:

          A surefire muzzle brake or flash hider weighs 4oz.

          Hacking up the lower for no reason other than “LOOK GUYS!” … saves 2.7oz.

          • tts

            If you’re saving 2.7oz then its not just about “L@@K GUYZ!1!”.

            Is this a lot to go through just to save that weight?


            But if you’re trying to build the lightest possible AR15 you can and have already shaved off all the other weight you have to go to extremes like this to get more weight savings.

            Also the target market for parts like this aren’t going to use a Surefire muzzle brake or flash hider. Too heavy. They likely won’t use any muzzle device at all except for perhaps a A2 birdcage.

            If this was a very expensive part then yes I’d say it was silly to bother with but if they actually manage to sell them for ~$150 then that isn’t ridiculously higher than what a lower goes for anyways.

  • Phil Hsueh

    As somebody posted over on SSD, this lower would have been perfect for Jesse James’ POS pre-weathered/worn, skeletonized AR that he’s offering.

  • Hunter57dor

    are we forgetting the numerous failures of the famous chauchat rifle?

    introducing more holes into a platform that is absolutely notorious for not liking fine dust is just begging for trouble.

  • Laserbait

    If they offer it, I will buy it – that just looks so cool! I have so many other “battle ready” lowers, this would be a great fun one! I wonder if they can/will offer a similar treatment to an upper, although I think I’d build it with a piston to help keep the gas out of my face.

  • J.J

    I would want one that is made of magnesium and either Coated or wraped in something like carbon fiber

  • JumpIf NotZero

    32% sounds like a big number!!! Until you realize it’s 2.7oz….

    • Ken

      Also, removing weight from the center of mass will be much less perceived than losing weight from the end of the barrel or anywhere further from center.

      • JumpIf NotZero

        Correct, and good point. Changing the flash hider or muzzle brake to a lighter one would be way more noticeable.

        • jcitizen

          How ’bout a Carbon – 15 lower at 3.90 oz.? Seems like the deal to me!

  • ChrisH

    With the direct impingement system, wouldn’t this mean that the hot gases and carbon would be spitting in your face?

    • JumpIf NotZero

      You read too many advertisements for piston systems.

  • Maximilian Johannes Benning

    I’m not worried about reliability as I wouldn’t put this in a SHTF or HD rifle. It would go into a casual plinker or something that I won’t be shoveling dirt into and then run-n-gunning.

    That being said it is only one ounce lighter then the MAG magnesium lower, which is $140 right now. It would be interesting to see a skeletonized magnesium lower or something that has a considerable weight drop. But at this point, I would only buy one because they look cool, as there are no advantages over the solid-design MAG lower.

  • Drapetomanius

    Are any of you people headed to the western front? This is fine for some purposes; suboptimal for others. We all sit here and snipe like everyone who buys an AR is going to the sandbox next week, and it just ain’t so. Recognize that there are a variations, enjoy the innovation, and see where it goes. /rant

    • JumpIf NotZero

      No… The difference is you can have the real-deal, take it to the range twice a year, never clean it, and it’ll still work when if you ever need it to.

      Or you can have some range toy gimmick.

      The idea that anyone would pay more for the range toy gimmick and then just wave their hand saying, yea, I know it’s not dependable but LOOK at it! Is dumb.

      • Disgusted and Annoyed

        Sounds like the same people who put spoilers and racing stripes on Kias or stick huge tires on a 2WD Jeep.

  • Josh Creel

    As an instructor I would love to have one. Its not a huge investment to build one out with stock parts and slap it to an upper.

    • JumpIf NotZero

      I’m not sure how you teach that you need a see-into lower…

      The only actual reasonable thing I can see with this is for people that are doing highspeed work, you can see the hammer position.

  • JT

    I could see this as a prop gun. That won’t sell widely unless they can convince people to buy guns to put on shelves that they should never use in a dirty, humid, ANY environment.

  • steveday72

    Would be very useful to have for tuning trigger actions on.

  • derfelcadarn

    It required decades to make the original M16 platform function if even the word dirt was mentioned near it, I cannot see this being a practical idea from any standpoint.

  • camosoul

    Why do people go to such extremes to save weight on an already light platform that barely gains them anything? My RFB weighs almost 20lbs with a full mag and glass, and due to the location of that weight being all back by my shoulder, I’m still on target faster than my 8lb .300BO… Bottom line, it’s an AR-15… I don’t understand why people insist on polishing turds. Quit trying to make it into something it’s not.

  • JT

    I love the way the guy in the video looks at the camera like he just proved something. Will this still function after a cord, piece of clothing gets stuck in it? Will it function like this after repeated exposure instead of just taking of the shelf out and firing it?

  • BryanS

    Reminds me a bit of this paintabll gun, which was done by a jeweler as a show piece (but at the same time can be functional)

  • Shooter S. Thompson

    I’ll buy one. Use it on my dedicated .22LR upper.
    .22LR runs crazy dirty.
    If running dirty at the range.
    A few shots with carb cleaner followed by a few drops of oil and clean lower.
    Problem solved.

  • Bryan McConnell

    Kinda cool novelty. I might build one for display. Would be fine for going to range. Wouldn’t be a choice for general use though. The dirt vulnerability of the AR upper receiver is legendary. Making a new ingress for FOD isn’t a good idea for anything except a range queen.

  • Willshortly

    Not for me.
    But that’s just my opinion.

  • Evan Samora

    Simply retarded. 2oz. Wow.

    An AR-15 is not that heavy.

  • mcrognale

    Ridiculous. The weight reduction is only .163 pounds. That is infinitesimal in the grand scheme of the gun.

  • Skizzums

    c’mon guys, we know this isn’t about weight savings, it’s all about looking cool. and in my opinion, it does. I think it looks fantastic and if it’s simply for a range toy, who cares. I wouldn’t be apt to spend any extra $$ on one, but if it ran and was in the 100$ range, i’d grab one just for the novelty. who cares if the dirt causes a malfunction here and there, I have a safe full of lowers for “work guns”, and this would def go into the “play” guns.
    I like it, and it’s people like me that they are selling this too, why are so many in such an uproar about it, if you don’t like it, then don’t get it…….WHO CARES