Howdy all,

Quick question on the BiPoly, as I’ve only built 80% AR builds up to this point. It doesn’t appear it takes a standard buffer tube; is there a way to run a traditional stock on the BiPoly setup, or does it have to be one of the printed stocks that come with the file pack? Obviously it’s not threaded for a buffer tube, but it would be great to be able to run a standard multi position AR stock on it; I haven’t been super happy with the printable 3 position.

Thanks

  • notsuspektEnglish
    6·
    3 days ago

    The bipoly makes no sacrifices on strength, that fixed stock is king as the buffer tower is traditionally a weak point. If you want to run a buffer tube and a collapsible stock, something like the Defiance or SL-15 are more appropriate.

    That said, don’t sleep on the bipoly. It’s 100% my favorite lower and worth building one for yourself.

    • literallyjustmaxOPEnglish
      2·
      3 days ago

      I guess I’m missing something in the build; I printed the PRS style stock, but how does the buffer get held into it? I don’t see a set screw point for capturing the buffer and spring inside the stock assembly.

      • notsuspektEnglish
        2·
        2 days ago

        That’s a great question, the bipoly’s creator determined that including a hole for a buffer detent would lower strength so there is none, you hold it back while you install the upper.

        Like I said, it makes no sacrifices on strength. My pla version is well over a year old with thousands of rounds through it and I’m not the only person with these results. I think he was on a good path with this one.

        • literallyjustmaxOPEnglish
          2·
          2 days ago

          I printed the lower in PA6-CF, guess I’ll have to give it a shot (pun intended). Probably will end up Form-1’d with a 10.5” upper in .300 BLK. Thanks for the tips, I’ll see how she shoots :)

          • notsuspektEnglish
            1·
            2 days ago

            You’re gonna love it. I’m gearing up to print it in one piece, no seam like a Monopoly.

        • The ShittinatorMAEnglish
          2·
          2 days ago

          Worth noting the Mono-Poly also ditched the buffer retainer if you printed the bisected model.

  • ClemensXIVEnglish
    3·
    3 days ago

    You could also print out a UBAR3 lower. It can take a standard buffer tube and it’s held in place with a u-bolt so it’s pretty strong. You can print it with or without an integrated pistol grip. The integrated grip is definitely stronger but not everyone will like it. https://guncadindex.com/detail/UBAR3-X:1