How to Pin a Collapsible Stock

Learn how to easily pin a collapsible stock to satisfy the Assault Weapons Ban (AWB) criteria with a drill, roll pin, and epoxy.

Blind Pinned and Epoxied Stock
Blind Pinned and Epoxied Stock

Note the disclaimer that this is for educational purposes only and that you should double-check all laws surrounding this.

Tools Needed

  • Drill & Bits: Hopefully you have something at home or can borrow someones since you’ll only need it for a second.  I went with a 1/8″ drill bit but as long as you can match up the bit to the roll pin, you’re fine.
  • Roll Pins ($13): I bought a monster pack since I’m always losing them in AR builds.  This one will definitely have several 1/8″ roll pins.
  • Epoxy ($6): I went with a plastic bonding epoxy since you want it to stay to the polymer rifle stock.

Pinning a Collapsible Stock

I’ll be pinning my Bravo B5 stock ($60) but this should translate to any adjustable polymer stock.  I like the B5 since it’s really light and has that angle that gives me a really good cheekweld.

First make sure that you have your stock in the correct length.  So if you have any optics (Best Scopes & Optics for the AR-15), make sure you have proper eye relief and length of pull.

1/8" Drill and Roll Pin
1/8″ Drill and Roll Pin

Get a matching set of drill bit and roll pin.  I’m using 1/8″ for both since it looks pretty thick and should stand up to some abuse in the rare chance that my collapsible stock tries to move.

Drill Press
Drill Press

Use a hand drill or drill press to drill the stock and the bottom part of the buffer tube.

Drill Through One Side Only
Drill Through One Side Only

Make sure to not drill through the entire buffer tube.  You want to just clear the first wall.  Reason is we want to make it a “blind” pin so you can’t just knock out the roll pin from a hole on the other side.

Pin In
Pin In

You might have to trim the pin depending on the initial length.  But make it so it will fit all the way to the wall of the buffer tube and be near flush with the stock.

I just used a pair of wire cutters.  But you can see that mine is a little too long for taste so I added some liberal force with a punch.

Blind Pinned and Epoxied Stock
Blind Pinned and Epoxied Stock

Mix up some epoxy and put it over the hole.  Since the roll pin is hollow you might have to reapply so that there’s actually epoxy over it.  And…you’re done!

Here’s a video of the process too:

Alternatives to Pinning Your Stock

Something new has come along…the Stock Lok ($35).  It swaps out the adjusting pin in your stock so that it becomes fixed.  Perfect if you don’t want to pin after reading this tutorial.

Stock Lok
Stock Lok


Looking for more help in building a featureless rifle or upgrading your AR-15?  Check out our AR-15 Resources!

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In the write-up you say to make sure to set the stock to the length you want. But then in the video you mention you can’t havd it all the way in, shortest length, according to the law,
Is that true?

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