Well, I haven't done this nor know of any one who has, but I figured I'd ask.....

Okay, how many of you have 'lost' the take down and pivot detents when assembling the lower?  I've lost two on one lower....

Any how, after looking at the detents.... I was thinking. If one had an old U-joint around, couldn't the roller bearings from the joint work?  I mean, take a bench grinder, needle nose pliers and grind one till it was just right.  I haven't taken a caliper to the 'spare' detents and the needle bearings to see if they are the right diameter (yet).  Just a (dumb?) trick I wanted to throw out to get an opinion....

So any one else have 'cheap' tricks they're willing to share (pertaining to AR's or firearms....)

Rolled pins are as close as your True Value hardware store.

I can make a detent from a drill bit shank in a few seconds.  No big deal.

Applying a few dabs of black hi temp silicone where the handguard engages the front mount, and  in the groove inside where the handguards engage the teeth of the barrel nut will still allow them to be easily removed, but will make the front end much firmer, and no creaking.  I wrap a tie-wrap around the base of the front swivel to stop that from rattling, or leave it off the rifle altogether.

I spray the tail of the bolt with dry moly lube after cleaning to help prevent new carbon build-up... or it at least slows it down.

When fooling with small parts... keep an old speaker magnet handy... you can pass this around  the floor or bench to find your lost parts.  Radio Shack usually has one or two on the shelf.