Stripped lower

[Tirod]

Insert the spring and detent, rotate the pin 90 degrees so the channel won't engage it, use the pin to depress the detent, insert, rotate back and lock it in.

When building the lower take a big hint from watch repairmen. Their workstations are always confined, with tall sides. Basically to confine parts and keep them close if they fly out of the mechanism.

Build the receiver in a cardboard box turned on it's side. There's only one escape and it's past you. Don't assemble in a carpeted room, bare hard floors are better. You find the parts.

I'm reminded of a highly respected carburetor rebuilder who worked in an empty shop. He literally tore down the carburetor on the concrete shop floor and left the parts there until reassembly. Parts can't go bouncing around the shop when you put them on the floor to begin with.

It's either that or feed Kirby sitting in the closet.

 

[Blade First]

"10-15 minutes if the front pivot detent plunger doesn't go flying across the room."

As cfullgraf suggests, pick up a 1/4" clevis pin...I get mine at Lowe's for $1 apiece. A small flat-nose punch will allow you to insert the spring and detent through one of the holes and into the channel.

Rotate the pin with the punch to capture them. Push the pivot pin against the end of the clevis pin and...bingo...no launch, no fuss.

For a newbie on a first build, recommend using a gallon Zip-lock bag to keep parts from reaching near-Earth orbit.

And please do wear safety glasses!

For the bolt catch roll pin, put a gentle taper on one end of the pin and then use the proper size roll pin punch and a tiny bit of Frog Lube to start the pin while holding it with a hemostat. If you're considering building more than one AR, buy a roll pin holder of the proper size.

Capture the bolt catch assembly with a section of a Q-tip shank and the pin will easily drive it out. No muss, no fuss.

If you're really anal about avoiding scratches on the side of your receiver, tape on a section of an old credit card that will act as a shield in case the punch slips off the end of the roll pin.

One more: give up on driving that big roll pin into the trigger guard tabs. Buy a kit with threaded brass inserts and 2mm allen head screws to replace the roll pin.

Less than $10 and it will work on alloy or polymer guards if you have access to a 5/32" drill. Quicker...and most importantly...much safer.

 

[tactikel]

First took 45 minutes. Tips; lube all pins and holes, use duct tape to mask,to prevent scratches, for that trigger guard roll pin: lube and slightly taper the roll pin with fine sandpaper, then use a phone book to insert enough pages to firmly support those "dang" ears, gently tap your roll pin it should set with no problems. Good luck!
BYW for the detects I used a razor knife tip to hold the detent in, the first try and it jumped I found it and learned how to hold it tight.

 

[Dr.Rob]

Take your time, do it right it's not a race. Tape will prevent scratches, a set of proper punches make the job easier.

Second time will go faster.

 

[Quentin]

Take your time, do it right it's not a race. Tape will prevent scratches, a set of proper punches make the job easier.

Second time will go faster.

I agree, who cares if someone else can do it in 15 minutes while it takes the first time builder two hours. Triple check your work, get it right the first time and forget about the clock.

 

[Field Tester]

For any springs or pins that get lost, try this trick.
Take a stocking out of the Mrs. drawer and affix to a vacuum cleaner hose with a rubber band. It makes finding small items a bit easier.

 

[USAF_Vet]

Built my first lower a couple days ago. Took me about an hour, start to finish, which included the time spent looking for the lost pivot pin detent, giving it up for lost, and making a new one. Would have been less time if I had done a couple things differently, like remembering to lube the trigger guard roll pin and hole, and using a plastic bag for the pivot spring and detent. Also, not being stubborn and going downstairs to get my pivot pin detent installation tool.

 

[Mike J]

I don't have roll pin punches but I picked up a tip from online. I took some small fuel line I had laying around from working on a string trimmer & slid it over the end of the punch & the end of the roll pin. It kept the punch from sliding off the pin until it was almost completely in. It took me longer than many here have posted. I wasn't in a hurry though. Just take your time & get it right.