mcg68 rebuild

For a few years I've wanted to rebuild one of my MGC68's into an accurate replica. After collecting drawings, parts, machinery, and tooling I'm finally able to start.

Yesterday I turned a steel barrel. I had to reduce the area for the front sight by 1mm since the airsoft part I'm using is smaller than a real part. That made it too small to thread for the barrel nut.

I found a drill bit that fit the bore of a 9mm barrel. With it I drilled the new barrel 1.5" deep. I wanted to go deeper, but my lathe wasn't happy.

I still need to mill the flat for the sight base and the slots to mate with the trunnion. I'm going to wait until I have the rest of the part ready to mill. Then I'll set up my dividing head.

Today I worked on making the trunnion. I made it to MGC dimensions except for the 2 prongs at the end. I chose to locate the barrel that way since it's the way the mp40 was designed. It was also easier to make than having the MGC style key.

It still needs the resting bar/sling mount slots. I'll do that with the dividing head along with the 2 attachment screws. The ejector slot I'll wait until it's mounted to the receiver then mark it with my new bolt. Then I can work on the feed ramp.

very nice work

I turned a new barrel nut. I found out that I didn't have an internal threading tool, so I wasn't able to finish. Once it's threaded all the parts are ready for milling.

The last part to make was the half-moon washers. Their made to the same dimensions as the MGC except they are sized to fit the tabs on the trunnion.

I replaced the rear sight with one from a SRC airsoft replica. Dimensionally it's very close to a real one. It has all the same parts. The biggest difference is the top front and rear edge are square. The drawings call out a 2.1mm chamfer so I scribed some lines and filed the chamfer.

The paint on these is rather hard to strip. Since the base is steel I burnt off the paint then wire brushed off the remains. The zinc parts can be stripped with permatex gasket remover. There are 2 ejector pin marts on the face of the 200m leaf. I sanded it on a flat surface until they were gone.

I drilled out the 2 rivets holding the original sight. Then welded on the new base.