2020-10-23 (F) Weekly Summary

I started a project that was unusual in two ways. The most obvious was that I was working on a firearm, and the second was that I was following the standard directions. I bought an eighty percent receiver to make a gun. I started by milling out the area where the spring-loaded trigger components will go, also known as the fire control group. I didn't do a perfect job.
First pass with a milling bit

The next time I milled, I went closer to the edges to match the red jig, and I focused on cutting straight lines. Sadly, I cut too deep, and my receiver's bottom is now thin plastic where it should be 1/16" (3mm) thick. The edges cleaned up nicely because it is nylon.
Second pass and clean

The errors I made were partially due to me failing to read the directions, but the next part is entirely my fault. I tried to install the bolt catch release lever according to regular instructions, but I was supposed to insert a small pin and set screw. I jammed the rod in so hard that I couldn't remove it, even with pliers. I needed to heat it with a soldering iron to soften the plastic so I could yank it out.
Heated extraction

After the third round of milling, I finally inserted the trigger and hammer components. Springs for the trigger rest on the floor of the fire control cavity, and that is where I have thin plastic. You can see in the picture that it is almost paper-thin and even tore when I applied some pressure. It seems to function because the springs don't press there, and the trigger holds in place with a pin. I suspect I could cut out that thin plastic, and it wouldn't hurt anything, but it would allow stuff to fall into the gun.
Trigger and thin plastic

After everything I learned from milling out the gray receiver, I wanted to start a new one and demonstrate the correct way to do things. I bought two receivers, so I started on my second, a white one. This time I always erred on the side of not taking out enough plastic rather than too much.
White receiver

As expected, I needed to make a few passes to remove all the plastic, but taking the extra time, paid off. The included jig overhangs the cavity, so the best way to clear this area is to force the milling bit over. Even then, I took out a little extra by the hammer pin holes and the trigger pin holes. The best tool for cleaning up the edges was a rotary tool with a sanding drum.
Taking more off the sides

The rest of the summary posts have been arranged by date. First time here?

Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7

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