DATUM Gear Releases Kevlar 80% AR Lower

Personally, I have never been a real fan of the polymer lowers for AR’s.  But one company is making a polymer lower that is Kevlar reinforced, making the polymer lower more resistant to flexing and even breaking under load.  I am not an engineer, but from what I understand about fiber reinforced polymers is that as long as the fibers are oriented properly, it can add strength to the polymers.  It can also help to contain pieces in the event of a catastrophic failure, meaning there is far less polymer shards flying around to harm the shooter and those in the immediate vicinity.

I know there are other Kevlar reinforced lowers out there, and I have not heard of any failures, so there may be some merit to them being a happy medium between true polymer and metallic lowers.  Time and the internet will tell the tale as people buy, complete and build these lowers for use.

Embedded in the post below is a presentation by DATUM Gear on their polymer lowers, as well as a short video of their lower.


  • johnny

    tale not tail

    • Cymond

      and flying not flaying

      • I took care of it—-

      • Giolli Joker

        The idea of being flayed by a plastic shard was way more horrifying than the kaboom itself…


  • jordan Hyers

    Sounds like they melted down some helmets into lowers and put it on their shelf but I wouldn’t mind having one for that kinda cool factor that it is kevlar

    • JumpIf NotZero

      Aramid don’t melt.

    • Melty injection molded plastics are thermoform polymers. Kevlar helmets, carbon fiber car parts, and fiberglass boat shells are all thermoset composites that don’t melt. They might feel the same to the touch, but are two different things.

  • Texas-Roll_over

    also known as composites…

  • Spencedaddy

    the largest problem associated with kevlar is that it is basically impermeable, carbon fiber allows the resin to flow throughout the fiber and lock it into place, the kevlar basically ends up like a fishing line in a piece of clay, it can move around, the best way is to combine these fibers and gain both of their advantages simultaneously.

    • Hmm, so if the Kevlar doesn’t increase the tensile strength of the polymer, then this is just a gimmick?

  • Some Rabbit

    How do you mill it out without leaving the inside all fuzzy? Maybe you have to burn off any kevlar fibers peeking out of the plastic.

    • We shall see Thomas will be working one up for review.

    • JumpIf NotZero

      Very short fibers. Think glass filled nylon and not resin/composite cured.

      Basically, the reason the average guy would be able to work with this, is the same reason it’ll be nearly identical to a glass filled nylon (typical plastic) lower. Which is to say, no stronger than a good plastic lower.

      The fibers in this won’t be long enough to add strength as the name and marketing imply. The fact they are implying so sort of puts me off. In this case, the “kevlar” (aramid fiber with a Dupont trademarked name) is just a filler to the polymer (almost certainly nylon). I really don’t think these will be any different than other lowers on the market.

      If they were… They’re be too hard for average dude to work with. Anyone that’s ever cut aramid cloth knows this first hand.

  • opie

    they most likely add kevlar pulp into the nylon…of course it would add more strength and abrasion resistance compared to normal glass filled. so i think there could be a benefit. however them showing it being ran over before milling the FCG pocket is kind of dumb…with all that material there it adds a bunch of strength… that and the pressure is spread out…i wonder the cost. if cheap enough i might order one for a pistol build(even if i hate rifle caliber pistols) but only would build one so i can shoot at the free range that only allows pistols,rimfire and shotgun…

    • Generally, if the polymer lowers break, it’ll be at the hoop for the receiver extension. I actually find it impressive that the “hoop” survived being run over like that.

      • opie

        yep you do have a point, they also fail at the rear takedown pin as well. thats the most high stressed part of the lower. then again with a buffer tube installed it would increase hoop strength, however that type of stress is not put on a lower unless your using it as a lever of sorts lol. im thinking it might have more strength than a standard glass filled due to the kevlar. also note as long as the fibers are bound close together they will add strength. though id like to see one that was saturated kevlar sheet and kevlar filled nylon. would be pretty strong but cost would not be worth it…can mill an aluminum lower with just a drill press and plunge milling using the drill press takes long but can be done…of course weaponsguild.com has all the tutorials you need…i loathe ar15.com for instruction on building things.

  • joethefatman

    So. Kevlar. A bullet proof gun…

    Silly I know. But someone had to do it.

    • gunslinger

      so bulletproof that the bullet can’t be fired!

      • mig1nc

        Bi-directionaly bullet-proof?

  • Robert Dean

    I’m surprised that they used kevlar. I thought McMillan stocks used fiberglass because of the greater strength and rigidity than kevlar.

    • Leigh Rich

      Kevlar fiber is mixed in with the Poly when injected. Not a new ideal. EP Armory has always done it.

  • gunslinger

    haven’t see on fail? time for some destructive testing!

  • Leigh Rich

    Wait until the company releases a n ATF letter with the 80% saying it is NOT a firearm.

  • michel Baikrich

    Woven layer in Kevlar layer with Polymer resin, or tritured short fibers with Polymer resin ????

    With polyester fiber obtained a better result, known as polyester possesses more elongation (2.5% for Kevlar – 25% for Polyester)



    Ballistic & weapons Eng. (Liege-Belgium)

  • mike

    Kevlar in 80% lowers is not new. EP80 claimed to use kevlar in their lowers as well.

  • Magoo

    UGHH why does no company just make a completely normal polymer lower, but with a reinforced buffer trunnion? That’s the only real problem with polymer AR-15 lowers. Just have a metal insert there to take the beating and keep it from ever snapping, same idea as the metal rails on a Glock. I’d pay more for a completely trustworthy and practical polymer lower than I would for a 7075-t6 one.