With regards to the CZ 452's and 455 rifles, if you use a standard 22 caliber cleaning rod there is more than a little chance the rod is going to drag across the rifle's ejector scratching the rod. The ejector is the sliver U shaped piece of steel that goes around the magazine well cutout in the action and is screwed on. This will occur even if a bore guide is used. Coated 22 rods tend to get peeled. Use a 17-caliber rod and you won't ride over the ejector. Patched jags may not willingly go down the bore, but this depends about as much on the cloth patches thickness as it does on the jag itself. Three CZ bore guides a Possum Hollow and one an M Werks and one a custom aluminum guide. There all for 17 caliber cleaning rods.