A few thoughts on CZ and CRF...
Roughness / Smoothness of the CZ / ZKK
If you are observant of contact points on the CZ/ZKK (these are iterations of the same action coming from the same plant, before and after the fall of communism), and if you are willing to spend two hours with the appropriate fine grit sand paper and valve grinding compound, you will be positively amazed at how slick a standard CZ 550 will become for a grand expenditure of about a few pennies (excluding your time).
Check specifically:
1) how the central edge of the magazine follower plate binds inside the grove for the ejector blade in the under side of the bolt (solved by rounding the central edge of the follower);
2) how the burrs of the ejector blade grind inside the ejector grove of the bolt (solved by deburring/polishing the ejector blade);
3) how the burrs of the lower rear bridge machining grind against the bolt (solved by deburring/polishing the machining of the lower rear bridge);
4) how the forward edge of the extractor collar binds inside the upper rear bridge (solved by rounding the edges of the extractor collar and polishing the inside of the rear bridge);
5) how the machining burrs on the inside and lower faces of the feeding lips grind against the feeding cartridges (solved by polishing carefully - but NOT REMOVING MATERIAL from - the feeding lips).
6) coat liberally the bolt with valve grinding compound and cycle the bolt one thousand times while watching TV.
Again, you will be amazed at the results...
Let us keep in mind that Rigby themselves used ZKK/CZ actions for years for their own rifles when Mauser stopped the production of true magnum-length actions. This is not faint praise for the action.
CZ safety
Regrettably, the ZKK/CZ does not offer a true safety, i.e. a safety that blocks the firing pin (either with 2 positions as on the Weatherby Mark V, or 3 positions as on the Winchester 70 and derivatives - sideways, or as on the original Mauser - "flag safety"). This is its only true shortcoming of the CZ, and where a Win 70 Classic has a true advantage over it. Instead, they offer a sear blocking safety WHICH CANNOT PREVENT THE PIN FROM FIRING THE GUN SHOULD THE SEAR SLIP for whatever reason (e.g. the gun falling, or a defective trigger "tuning").
Aftermarket firing-pin blocking safeties are widely available for the CZ (Lapour, Gentry, American Hunting Rifles, etc.) and the machining to install one is mostly limited to drilling one small hole in the bolt handle with a carbide bit and fine-tuning the engagement of the camming surfaces, which is a little tricky.
Installing a firing-pin blocking safety is probably the one "mandatory" upgrade someone needs to make on a CZ in addition to an action job.
CRF
Yes that monster extractor is reassuring, but this is NOT the primary advantage of a CRF.
The primary advantage is that a CRF prevents double feed, or in other words, it avoids unwittingly loading the chamber. A push feed bolt will chamber a cartridge and NOT EXTRACT THIS CARTRIDGE IF THE BOLT IS NOT CLOSED, i.e. if the extractor is not snapped over the rim when closing the bolt. The consequence is that one can actually load the chamber without turning/closing the bolt; pull the bolt back; see no cartridge (if there is no other round in the magazine); and close the bolt on a loaded chamber while believing the rifle is empty.
The importance of this was illustrated 3 years ago in the Eastern Cape when one person inadvertently loaded a gun by pushing into the chamber the one cartridge that was in the magazine; forgot about it in the flow of the discussion; and handed the rifle, bolt open, to someone else who, seeing no cartridge in the magazine, closed the bolt on the loaded chamber and put the rifle on the back seat of the truck. The next person who grabbed the gun from the back seat depressed the trigger while doing so, and the gun fired. One woman died. I personally know the people involved, this is a true story.
A CRF bolt would have been carrying that cartridge back out of the chamber even if the bolt had not been closed during gun manipulation. THAT is the primary benefit of a CRF on a hunting gun.
Of course there were a long list of gun safety violations along the way, but CRF would likely have prevented them from resulting in a death. I personally ALWAYS cycle the bolt and dry fire my rifle in a safe direction 3 times before putting it back in the case. In my military days, during the 3 year officer training at the Special Military Academy the violating the '3-safety-manipulations-and-dry-firing-in-a-safe-direction' rule was worth walking back from the firing range to the barracks, and this was a long 3 hour walk. We learned quickly and for life ;-)
