fill in barrel cut grooves

[Hood886]

how much material is left between the thinnest part there and the inside of the chamber? I'd be more nervous because of that location needing to withstand pretty significant pressure.

The Grove is supposed to be there, it's how the barrel headspaces. He is trying to figure out how he needs to headspace it correctly.

 

[acmech]

I've redone an AK barrel groove like that before. Find something the right dia. to fit into the groove, some kind of mild steel. rod, a nail maybe though nails aren't mild steel. Cut it to length, but a little shorter. Weld it on each end then grind the rest down. You just filled the slot with as little welding and heat as possible. I have a video up on youtube but I can't remember which one it is where I did just that. It might have been one of the ones they deleted to terms of service.