I am assembling my first lower today, everything is going along smoothly, no problems, get the trigger in and then,,,,where the hell is
the hammer pin??

I am pretty sure it was in the parts kit, I thought I remembered seeing 2 of them, looked everywhere, can't find it.

Went to fastenal, to see if I could find something to match up, no luck.

So I guess it's put everything away and order a new pin and wait.....this sucks.

Carpet monster?

I ordered a pin from brownell's and remembered I needed a stock wrench anyway, and brownells' is only 150 miles from me so shipping should be quick.

Just sucks to get all set up to do it and have to stop.

Ate a detent and detent spring on me!!  Thank god for "Oh Shoot" kit.

Don't waste your time and money ordering just a pin.

Buy extras of all those small parts.

BTW, I keep an old woofer magnet taped to the end of a broomstick.  I sweep it around to find small parts like that.

Every time you order, get some bits and pieces.  We are talking 50c and dollar parts.  Soon you will build up a spare parts kit so that when you have such a problem you just say, "Rats!" and get another one out of your spare parts kit and go on about your business.

A complete bolt and complet lower parts kit is a good starting point.

BTW, the hammer/trigger pins are unique to the AR.  Those grooves are precisely located for a reason.

Roll pins may be bought in most any hardware store, and if too long, simple cut to length with a Dremel cutoff wheel.  The end may be reblued with some touchup blue.

Springs, I'd rather have the correct AR-15/M16 spring than a make do item, though I understand the spring from a Bic lighter may be used in place of the safety/selector detent spring.

If you hand me a stripped lower, stripped upper, and a barrel assy, I can literally complete an AR-15 from spare parts.

Get the big ass magnet and canvas the carpet, it must be there

If the grooves in the pins are important, then is there a right and wrong direction to insert them?

Oh, and a single pin from Brownells is $2.38, I thought it would be a buck at most.

I have searched and searched for the pin, I am actually starting to think it wasn't in the kit, because it could not have gone far.

The pins can go in from either direction. The center groove in the pin is for the hammer retention spring (look inside the hammer pin hole), this holds the hammer pin in. The outer groove is for the hammer main spring arms to sit on top of. In theory if the hammer spring arm (either one) sit in a groove the pin will not come out. Occasionally they still come out.

That's what they used to cost, maybe $1.50, not more than a year or two ago.

Well, the pin and wrench got here the next day and I finished putting it together no problems except the wrench I got sucked big time, it didn't really fit the castle nut, I got it to grab enought to tighten the stock, but I will have to mod this wrench to make it fit  if I use it very often.

Just use the one from your "spares'kit" - since that's why we all buy them..  Problem solved and you can replentish your "spares kit" while test-shooting!