Magpul UBR install guide and pictorial review

[Stickman]

With the receiver extension (buffer tube) securely in place, you should see a setup similar to the below picture. Take the UBR stock, and press it over the receiver extension. It will probably be a snug fit, so use a little pressure if needed. In the case of mine, it was snug, but not what I would call tight, but it was certainly more "fitted" than the A2 stock it was replacing.

Take care that when you are pressing the UBR into place that you don't squash the spring that is sticking out of the receiver.




In the below picture you can see the spring, and its worth pointing out that this spring needs to go into place without being deformed. Take a little care, and you shouldn't have any problems. You should also be able to see the portion of the UBR that interfaces with the cutout of the receiver. Press the stock in and this piece should push into place.