Tennessee Arms Co Polymer .308 Lower

Tennessee Arms Co. is known for their polymer AR15 platform lowers is going to be making a polymer .308 lower as well.  The lower will be DPMS patterned, and feature metallic buffer collar and grip screw threading.  These are now in presale, and are expected to be available 2/1/15.

Not having had good luck with polymer lowers for the AR15, I am very dubious of polymer lower for a larger platform AR.  By the very nature of the .308 round, you are talking more stress and wear being put on the lower.  When talking to shooters I see the gamut of reactions to poly lowers, but it never seems to change my mind.  I am not a fan of poly lowers as I don’t see the weight savings in them when there are lowers that are metallic and are just a few ounces heavier, which can always been made up in a different component.


I will however say this about Tennessee Arms Co., they have always been a stand up company about their polymer lowers though.  I can remember their first run of poly lowers for the AR15 and the two generations having issues.  TAC stood by the product, fixing the problem and offering refunds, credits and new lowers to those who had issues.  With that in mind I would try one of their lowers, if for no other reason then to support a stand up company that stands behind their product.

I look forward to seeing them at SHOT this year where they are sure to have their new lowers available for a preview.

What say the readers?  Polymer .308 lower a good or bad idea?

Thanks Christopher for the tip!


  • BS

    I just picked up two of their AR15 lowers and I thought they looked pretty good. They seem solid and I did some rough flexing of them without a whole lot of movement. My only complaint is that they didn’t go a good job of cleaning them up; the drilled holes still had burrs and/or tailings on the back. Also had a very snug fit for a Magpul pistol grip.

    • BS

      Actually installed the parts kit last night and didn’t have any issues with a cheap-o pistol grip. I did notice the selector switch is pretty loose and won’t hold perfectly level, but it still seems safe to use.

  • John

    Don’t polymer AR-15s already have durability issues?

    • ClintTorres

      I think a lot of the problems that the early polymer lowers were having are just now being addressed by the industry in the form of enhancements in the weakest areas of the lower (buffer tower and rear take-down pin areas).

      • John

        That’s what I was kinda alluding to. The first polymer lowers were carbon copies of the aluminum ones, and problems arise due to unforeseen differences between polymer and aluminum. A re-engineering of the lower was in order but happened after the first gen lowers went out. I wonder if they foresaw the differences between .308 and 5.56 or is this simply a polymer lower scaled up

        • ClintTorres

          They’d be fools if they had not learned anything from their first mistakes. But one never knows.

          • mig1nc

            The new wave of poly lowers that started with Plum Crazy failed to learn the lessons of Cavalry Arms. Cav Arms had beefed up the common failure point. They are now caught up to where they should have been two years ago.

    • Chris

      Original poly lowers were carbon copies of the aluminum lowers. TAC built theirs from the ground up to be polymer, putting extra material near the stress points and metal inserts where threads need to be.

    • Gray Sanborn

      From what they’ve commented on forums, the only failure return was due to some overzealous flame polishing of their clear lower which they’re covering under their warranty from what I understand.. ( See: http://reddit.com/u/tnarmsco )

  • ClintTorres

    All my guns are range toys so I feel like polymer is fine. Don’t know that I’d take one to war (I would not take me to war) or any application that required hard use.

    The JMT 80% polymer lower I have on my AR pistol does not seem flimsy in any way. All the pins and selector lined up well. There isn’t any play between the upper and lower. And…it was a fun project.

    Time will tell but my initial impression of the JMT is positive.

  • me ohmy

    and they don’t get many back after they broke from shooting them.. example as a PISTOL build from ph43drus

  • Bp. David

    I practically had to give away my plastic Bushie after it developed a hairline crack and broke at the buffer tube threads. I wouldn’t give 10 cents for another plastic gun.

  • gunslinger

    if they can reinforce the stress areas, i don’t see an issue. but that doesn’t mean making a part metal and calling it a day. won’t the energy transfer to another “weak spot” but i’m sure there is a way to stretch that area out and make it plausible.