I started on my first lower today, but I need help to finish it.  I am having a problem with the safety selector of all things.  I followed the directions on this site (extremely helpful).  I installed the selector pointing up to the fire position, with the hammer cocked.  The selector moved freely as stated in the directions.  I then installed the selector detent, with the point towards the selector, the spring and grip.  Without tightening the grip, just holding it in place, the selector would not move.  I removed the grip and spring and checked the hole in the grip, reinstalled and same problem.  I then removed the spring and trimmed a single coil off, reinstalled, same problem.  When I removed the grip again, I noticed that the detent did not fall free from receiver.  Previously I had the receiver upsidedown while installing spring and grip so I had not noticed this.  I cannot get the detent out and the selector will not turn, even with grip and spring removed.  Please help.  I have tapped lightly on the receiver to no avail.  All parts are RRA, everything else went smoothly.  Please help, it is very much appreciated!

Hershey

When you get your detent and selector out, re assemble it without the selector installed.  There may be a burr in the detent channel, keeping it from moving.  Insert a punch in the selector hole and depress the detent pin a few times and see if it pops back up.  I always install my selectors with the lower assembled.  You can remove them by rotating it between safe and fire at a 45 degree angle and pushing it out.  Installation requires depression of the detent with a punch.  I hope you can get it back apart!!!!

DG

I used a drill bit to ream the passage behind the detent in an attempt to remove any possible burrs behind it.  Still no luck.  I just put the lower in the freezer.  I am hoping that the brass will contract more than the aluminum lower.  What do you guys think?  Or should I try heat?

Hershey

He got it fixed and commented in a separate thread.
[url]http://www.ar15.com/forums/topic.html?b=3&f=4&t=170403[/url]

From that thread...