10 November 2013

So Your Friend Bought You A MOE Stock Set

The handguards are easy.  Just make sure you have things lined up at the front.

The stock is easy.  It's just hard on the fingers to pull the little lever to get the latch past the end of the receiver extension.

Neither require tools.

The pistol grip requires tools and there are pieces that will fall out if you're not careful.

Tool.  A big screwdriver.  In most cases, this is a flat-blade.  CMMG and a couple other places use an allen head.

Here's how you should start.  Lower separated from the upper, hammer cocked, safety on, take-down pins pushed back in.

Next look inside the pistol grip to see what kind of screw you're dealing with.

Then remove it.  Lefty loosy.  Counter clockwise looking down like we see here.  Put the assembly upside-down on a flat surface and try to keep it oriented that way.  It's not hard to do, but it's a little clumsy the first time.  Don't pull on the grip, let it stay put while you remove the screw.

Once you have the screw free, pull the grip away from the lower slightly.  Notice this little spring?  You want to save that!  It's mostly up inside the pistol grip and it engages the safety detent in the lower.

With the grip off, there's nothing holding the detent in that hole.  With no spring pressure on the detent, there's nothing holding the safety-selector in its hole.  If you're too worried, tape the lever of the safety-selector to the side of the lower.

Here's what the selector, spring and detent look like if they come out.  Don't panic if they do!  The safety-selector can also fall out, again, don't panic.  They all go back in as easy as they came out.  The point on the tip of the detent goes into the hole first.  It rides in that slot cut in the barrel of the safety-selector.  The lever of the safety-selector goes on the opposite side of the detent's hole just in case you get a little lost.

Let's get aggravated!  It is best to start with the screw sticking out of the appropriate hole.  MagPul gave us two that are the same size and you want the one closer to the front.  If you look inside the grip, there's a recess for the screw head in the correct hole.  Use the screw that comes with the grip, don't reuse the one that came with the rifle.  To get the screw in the hole I balance it on the tip of the screwdriver and then lower the grip onto the screw.  Some tape to hold the screw to the driver helps a lot as well.

Put the detent spring in the small hole in the grip.

Hold the spring in place and put the grip on the flange.  Once you have it placed as pictured, the spring can't fall out.  Line up the screw at the hole.  The screw hole angle is not the same as the grip.  I've found its best to not even try to get the grip lined up here and to just get the screw started a couple of threads.  Notice the blue stuff.  That's a loctite analog.  It makes screwing the screw all the way in a chore, but it also keeps it from unscrewing itself.

Once you have the screw started, make sure the detent spring is in both holes.

Then push the grip down flush with the lower.  Now tighten the screw all the way down.  Rightie Tightie or clockwise looking down the grip.  Because of the blue stuff, it might feel like you've got it all the way down before it is.  To check, try wobbling the grip.  If it shifts, you have more tightening to do.


  1. Every time I see a slotted screw in a grip kit, it goes straight in the trash. I'd much rather spend time looking for an Allen socket/bit than fight starting a slotted screw. Did that exactly once.

  2. There is an entire lecture about the correct selection of threaded fasteners I'll skip here, I'll just put a mini-version below.

    A slotted screw is the correct fastener for this application.

    Allen keyed cap screws were developed for applications where a smaller head was needed because there wasn't enough space for a standard hex-head cap screw (not enough room for a socket or open end wrench) and larger compressive forces were still required to get the parts to mate. We don't need those forces to make a pistol grip work and we're actually putting too much force in too small an area with an allen head than with a standard screw head. Perhaps if you were using a washer under your allen head.

    There are real reasons to choose a standard screw head over an allen head that have nothing to do with ease of starting it. Load spreading on soft materials being the main one.

  3. Hi i must say you have given great information and nice post which is interested for engineers.

    ISO 2341 | DIN 1444


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