300 Holland + Mauser = $$$.
The 7X57 is a natural on a M98.
The CZ550 isn't a Mauser. Not even mauser like in my book. I'm not saying it's a bad action, quite good IMO. It's just about as much a mauser as a Remington 700.
Personaly, I would look for a nice Mexican smallring for a 7X57 and look elsewhere for an action for a .300H&H.
Terry
