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Another LPK question, I promise I used search first...

Discussion in 'Black Rifle Forum' started by phx223, Feb 16, 2010.

  1. phx223


    Apr 25, 2009
    Ok so I am about to buy a stripped lower and build it up. I looked up lpks like crazy and decided on the palmetto armory lbk that includes a cmmg lpk. That leaves me with a big question and a few little ones.
    It seems that the install is pretty easy, but I saw alot of posts that say its better to buy it complete because its installed by an expert. Is it really that easy to mess up that is better to use a pro? (I am more mech minded than the avg bear)
    Is the CMMG lpk a good buy? Better yet is it dependabe? The famous chart makes no mention of LPK's...

    Sorry for another boring LPK thread, but I am needy. And I promise I will post pics in a few weeks of a completed lower at the least...
  2. jdm0506


    Feb 3, 2009
    Just make sure you get the springs and detents right. The only real difficulties with installing a lower are getting the bolt catch assembly in without dinging your lower, and getting the pivot pin installed. I used a youtube video to build my first (I'll have to dig around and see if I can find it), while keeping up a copy of the instructions on The reference is good for identifying parts (some of those tiny little detents and springs look super similar), and the build guide is good. I found that using the video while actually building was more beneficial as I just learn better that way. Also, I'd get a couple of roll pin punches as they make things much easier.

    I don't know about CMMG lpks, but I've never really heard anything bad on them. I personally use RRA lpks as I'd heard good things about them. I have occasionally come across discussions on the DPMS kits where a person might have an out of spec bolt catch or something.

    Oh, and be sure to do your function checks as you're assembling your lower (safety and disconnector). And I suggest wearing safety glasses when putting in the pivot pin. I've had the detent go ballistic on me when the pin slipped. Lucky I didn't get hit in the eye or something and the only damage was a fat lip.

  3. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

    Nov 24, 2005
    I perfer Stag lower parts kits. I hava Colt lower, I priced a Colt LPK.
    Holy crap,.......$213! :wow:

    I have no idea why this would be four times the price of a Stag kit
  4. The bolt catch lever necessitates some finesse to not scratch or ding up your finish while the trigger assembly requires you to pay attention so you get the spring on the right leg or else you will get a light strike or no strike on the primer when the hammer doesn't go through its full travel.

    As for the other parts, grips, takedown pins, stock, buffer tube detent, etc., it's all easy and you can do it with one of your eyes closed. I figured it out on my own after having skimmed the Calguns OLL assembly sheet once.
  5. desertfox

    desertfox <font color="red">Suspended</font>

    Apr 6, 2005
    save the money and do it yourself. unless your start trying to polish things, your not going to screw it up to the point of danger, just malfunction......lots of material out there on how to install the parts, read it 2 or 3 times and have fun. once your done, you will be surprised how easy it was.
  6. jrrich


    Jan 6, 2009
    I did my first one last year and I learned a lot. There is nothing particularly difficult about it, but there are a number of hints and tips that make things easier. I did a fair bit of googling before I put it together.

    One thing I did screw up was the spring for the hammer. I did not install it correctly (upside down/reversed) and as a result, the trigger pin would walk with every shot. I finally figured out that the pin was held in place by the tension of the spring after I got home and took it apart. It's really easy to put in incorrectly.

    Assuming you are not a total klutz with tools, you can do it easily and it is a point of pride afterwards. You also get to understand the mechanisms involved much better.
  7. madecov

    madecov book em' Danno

    All of the above...............

    One other thing is not all LPK are equal. RRA uses a rolled steel pin that compresses and is easier to install. I would imagine that CMMG kits are re packaged DPMS kits.

    STAG has very good kits at reasonable prices

    You may save $10-20.00 on a kit now but a quality kit for a small amount more will wear longer and be easier to install.
  8. hottnucks


    Nov 11, 2007
    Hampton Roads, VA
    I like RRA parts kits the best. I find them on equipment exchange for $60 shipped all the time.