I had my CZ550 Safari Magnum converted to 404 from 375 by Pine River Lock and Gun, QLD. They did a superb job, using a MAB barrel, and reusing the CZ sights, as I like them. The rear sight island was done beautifully, turned as a part of the barrel, not as a soldered on island. Barrel bands were also great. I can provide photos if you like. They did ensure the cartridge feed was spot-on, and also did a great job on the trigger while they were at it.