If you are new to building AR lowers, there is one step that is, in my opionion, the most risky in terms of making a mistake and scratching the finish if not even gouging the aluminum. That’s when you go to install the bolt catch. You must juggle the receiver, spring, detent, catch, punch and hammer all at the same time while being right against the nicely finished receiver!
Historically, you had to get ready for battle and would tape your receiver to protect it from slipping punches or glancing blows by a hammer.
Installing the slide catch is way easier now with the right tools. I have really come to rely on three punches to get the job done. The first is a purpose specific punch set from Wheeler this is flat on one side and has a protective rubber coating.
Now plenty of guys can get their build done with the above. Because of my tremor, I like to drive the pin in the rest of the way by using a really long roll pin punch that safely clears the receiver. I have a Tekton gunsmith punch set and the 1/8″ roll pin punch works great for me.
I hope this helps you out. This is what I do every time now. It’s also what I use if I need to remove and replace an existing catch.
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