tapping lower take down detent

AR/M4 AR Technical Discussion
1

I remeber seeing an article on this but can’t find it anywhere. Does anyone know what I am talking about and where I can find it?

2

Here’s a recent thread on the subject.

http://m4carbine.net/showthread.php?t=22958

ADCO and Specialized Armament can do it for you.

http://www.adcofirearms.com/

http://www.specializedarmament.com/

3

Maybe this is what you are looking for:

https://www.m4carbine.net/showthread.php?t=4837&highlight=tapping+takedown+detent

Some of the pics seem to be gone so you may have to look at the links.

4

Assuming, from your original title, that it is the rear take-down pin detent (and not the front pivot-pin detent) that you are asking about, then the link provided above by g5m contains the correct info.

The existing rear take-down pin detent hole is already the correct size for tapping for a 4-40 set-screw so there is no additional drilling required. Just get the tap started straight and it should follow the existing hole with no problem and very little effort. Just use plenty of oil.

Quarterbore never really mentioned it, but the times that I’ve done this, I’ve gotten the best results using a “plug” tap rather than a “starter” tap. (YMMV)

HTH . . . Doug

5

Thank you g%m. That is exactly what I was looking for.

6

This is a bottom feeding modification to an AR15 lower.