Thank you for the info. Its an FA build (7/2). Figured I may could use Allen head screws, tack weld them on the inside, fill the head in with a little weld, and round it off.
Well, its always slightly embarrassing when you wind up answering your own question. It turns out that the recuperator was catching on a bad spot when the bolt was pulled to the rear keeping it from return the barrel forward. Cleaned it up and it cycles now.
I just looked at it again. The recuperator is not pushing the barrel back into lock. It and the bolt are going back and the bolt is sending it forward again.
The barrel can be installed and door closed. It can then be opened and removed, but after cycling the action the barrel locks in place (bolt to the rear).
We finally finished welding up our M53 build and fitting all the parts in it. With the recuperator installed, and after bringing the bolt back (FA), the barrel does not want to come loose and the door doesnt not want to come open. Any ideas what I need to look at adjusting?
The bolt I received with a 1928A1 kit from RTI has a M1 style safety notch cut into the bottom. Was this a normal modification or maybe a late war production?
Im looking for a WWII (or WWII pattern reproduction) of the MG42 barrel sleeve. A Google search didnt turn up anything other than the short write-up by BRP about the differences between the MG42, M53, and MG3 sleeves and boosters.