Working on an Aero M4E1 lower and I'm finding that the hole for the pivot pin spring and detent is not deep enough.  As best as I can measure it, it's only about a half inch deep.  From what I can find searching the intergoogle, it appears that the depth should be just shy of 1".  I've contacted Aero and I'm awaiting a response but I figured I'd ask here as well to see if my suspicions are correct.  I believe the size of the hole is 3/32".  Would a simple fix be to just drill it deeper?

ETA:  Nevermind.  I did the little trick of using the 3/32" bit and just spinning it by hand in the hole.  It released quite a bit of material that must have been left after the milling.  All is good now.

Hopefully this helps someone in the future though.

For reference, you should be able to see some coils of the pivot pin spring through the weep hole on the boss.

Good point.  However, these lowers don't have that weep hole.  Probably why the material built up in the hole and didn't flush out on it's own.

If you build enough guns, you will soon figure out to chase every single hole with the correct size of drill bit by hand, I have run into a lot of lowers that have flashing and slag in various milled holes.