AR Lower 4-40 Set Screw Modification 11-09-2020

I've done this to all the AR's that I've put together. Not really necessary but if you do change out your buffer tube or butt stock it keeps the detent and spring parts from being launched and most likely lost during disassembly and will also prevent the spring from getting mangled during assembly. There are a couple of manufacturers that already provide this feature and the take down spring and detent hole will already be tapped with 4-40 threads such as Aero Precision. If the hole has already been tapped by the manufacturer using a set screw is optional and it does not have to be used.