The slotted hole is to help with disassembly of the bolt (to separate the firing pin, spring and shroud assembly) but I don't know how it works. I emailed the distributers over here ("down under") and they didn't know how it works either and pointed out that it is not recommended that the owner disassemble to bolt anyway (apart from the unscrewing of the complete pin/shoud assembly from the rest of the bolt as enabled by the pin on the side of the shroud, which is as far as the owner would ever need to go) - I think it may even void warranty for this components.
The screw driver is for adjustment of the sights but is not very well suited for that task (probably already obvious) and the distibuters told me that too. I'm not knocking CZs, just pointing out a few of the realities - I'll keep buying CZs because they are good value for money.
There is another unusal thing they do - the CZ550 Magnums have an L shaped piece of metal that is used as an additional recoil lug under the rear sight base (have done this since Brno 602 days) and they provide a spare when you buy the rfle new. Can't figure out why - it's not going to fall out in a hurry and they don't wear out.
