Turn the magazine catch clockwise, which will screw it into the magazine release button. This will cause the magazine catch to protrude from the left side of the receiver. Once the magazine release button is threaded onto the magazine catch, take a punch and press it into the receiver. RELATED STORY: Lower Receiver Science – What’s Best Between Forged, Billet and Polymer?.Be sure to have the textured part of the magazine catch facing outward. Thread the magazine release button onto the magazine catch. From the right side of the receiver, feed the magazine catch spring onto the magazine catch. Slide the magazine catch into the left side of the receiver.

In your lower parts kit, you should have a magazine catch, a magazine release button and a magazine catch spring. Tightly secure the block in the vise and slip the lower on top of it using the magazine well.Ģ.) Install The Mag Catch Installing the magazine catch is very simple but, before you move to the next step, make sure you test it with an empty magazine to ensure you have set the proper depth. For the AR-15, a block is typically rectangular and matches the external dimensions of a magazine. You can assemble a lower without the use of a vise, but it will definitely make your life easier. One key is to have the correct tools like this vise block from Brownells, which makes installing parts very easy. If you do not want to machine your own lower, you can also purchase a stripped lower through a firearms dealer and build it out using this guide.ġ.) Set The Vise Block Aluminum and polymer lower receivers are very similar in terms of assembly. In this section I’ll demonstrate how to transform that finished lower into a functioning firearm. In the first part of this series, I showed you how easy it can be to turn a so-called 80-percent lower into a functioning lower receiver. From the ground up, you can select all of the parts to make the rifle unique and truly your own. An AR build is likely one of the most fun things you can do without being on the range.

Anderson lower parts kit install