Cz 527 American with 24” proof carbon barrel stuffed in it.

[Sinclair]

Don’t think it’s quite that simple here in the states. CZ barrels are metric threads, most regular gunsmiths here are setup to cut “standard” threads. Switching back and forth between metric and standard drives the cost of the labor through the roof and makes it impractical. At least around here. He did say, he thought PAC-Nor would/could cut metric threads on the tenon before shipping. Don’t know!

Don't know about "most" gunsmiths as I have always done my own work. But, unless you are using a pre-WWII made lathe, most modern lathes have a simple solution to switch between metric and "std" threads. Move a lever or at the most swop out the lead screw transfer gears and that takes seconds or at the most, 10 or 20 minutes.

I taught it to my machine shop students. If my "Juvenal Delinquents" could learn the procedure, certainly a practicing Gunsmith should be just as capable.