Preparations before a build

[M90A1]

on AR-15's, if not already tapped, I tap the hole for the take-down pin detent & spring for 2-56 set screw. it's a very common mod. Some AR-15 lowers come with that mod.

I think a 2-56 set screw is going to be too small for that hole. Are you sure you're not using a 4-40? I've seen some companies using a 6-32 even. I've been using a 4-40 for 30 years.

[rpoL98]

I think a 2-56 set screw is going to be too small for that hole. Are you sure you're not using a 4-40? I've seen some companies using a 6-32 even. I've been using a 4-40 for 30 years.

@M90A1 you are absolutely right. I'll edit my above post. I went and eye-balled the tap that I used, and lo and behold, it is indeed 4-40.
thanks for catching that. much appreciated.