The drilling out of the slide took a bit, I just wanted to remove weight. Don't know how much NEEDS to be removed, maybe try it as is to start. The mag was just a fiddle and the chamber reaming wasn't bad. I think I removed the barrel and masked off the reamer with masking tape to equal the fit into a Browning Hi Power barrel. The cartridge stands out the same distance after. I didn't even use a headspace gauge after. No need. It seems to me there was a country used them as 9mm...here's a thread you should read. Might give food for thought.

The Cuban Winchester | WeaponsMan