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BCM and compatibility questions

Discussion in 'GATE AR-15 Forum' started by Stepaway, Apr 15, 2010.

  1. Stepaway

    Stepaway Citified

    Mar 5, 2010
    Can you tell me who makes BCM lowers - I searched this forum, the Black rifle forum and didn't see the answer on their website. They appear to sell a lot of LMT equipment but I'd like to know for certain.

    Second question, is there true compatiblity among the manufacturers of uppers and lowers or is there some cross reference you can point me to that would identify compatability problems? I want to make sure when I buy my first AR that I have made a choice that will keep my options open in the future.

    Thank you for your time and patience.
  2. Constructor

    Constructor Moderator

    Dec 10, 2009
    I do not know who machines BCMs uppers or lowers and as far as I know there is no compatability chart.

  3. RainierArms


    Oct 23, 2004
    You shouldn't need a compatibility chart as most AR15 parts are interchangeable. There are times when you have a in-spec upper and and in-spec lower that will not even fit together. Since milspec calls for a certain amount of tolerance, if they are both at the opposite end of the spectrum, it may not work well together. You can have one set fit perfectly and another set be a rattle can or something so tight you need a mallet to put together. As stated before, I've had a very reputable company's upper & lower that didn't even fit together.