These 3/8" Leupold rings on a CZ 452 American are the size both CZ and Leupold recommend. The screw is not fully tightened (just snug) but the ring is tight in the dovetail on the right so tightening the screw can't pull it over any more to the left.

To me they are too narrow but I know next to nothing about rifle scopes and mounts.

The American has a different dovetail compared to others in the lineup. My rings have been like that since I got my rifle, it was long ago and I knew far less, I should replace them someday.

https://www.rimfirecentral.com...406317/#post-3588874

The CZ comes with their own rings, mine did. Cause the rail is a wonky metric size IIRC.

I’d send a email to CZ and find out

I just checked at midway and they no longer carry the rings but mention the rail is 11mm.
https://www.midwayusa.com/product/1008875749/

Also available on optics planet(but I’ve never ordered anything from them so I can’t recommend either way)

I've been told CZ's have come in both 3/8 and 11mm dovetails (I don't know the reasons or model history, all mine are 11mm). The 11mm certainly are the norm. There is a difference between the two and many mounts do not interchange. What you show in that picture is not acceptable. First step is measure the dovetail and see if its a 3/8 one or 11mm one. And then make sure the optic mount fits the answer. I do note that on some of the mounts that say they fit both sizes the clamp is different on each side so that you flip the clamp to the size of the dovetail.

CZ say the 452 American has a 3/8" dovetail, these Leupold mounts are marked that size. I did not measure the gun or rings. Where is the 3/8" dimension, on the top or between the grooves?

I just measured the 452 to see where the 3/8" measures.
Top of the dovetail is *barely* over .5" or about 12.9-13mm
Inside the dovetail is not quite 7/16" or 11mm

While at it I measured the 457 American which has an 11mm dovetail according to CZ.
Top of dovetail is not quite 7/16" or 11mm
Inside the dovetail is about 3/8" or 9,5mm.

a 3/8" dovetail should be 12.7mm an 11mm dovetail 11mm measured across the top max width.

Do you have the left side clamp-y part upside down? Some are made to be used both ways for different guns.

Of possible use to determine the size of the rail:
https://www.diproductsinc.com/Products.aspx?CAT=4268

If it is determined to be an 11mm dovetail rail, an Internet search for “11mm dovetail scope rings” produces results for several sources.

quote:

Originally posted by cas:
Do you have the left side clamp-y part upside down? Some are made to be used both ways for different guns.

I believe I tried turning it over but it only fit the one way. Regardless I returned them so now need to find gloss rings that fit.

Reading that reminded me that when I bought my CZ I couldn't find blued rings, and ended up with brushed stainless on it for a few years. However that's not what's on it now. Despite having no recollection of changing them.

quote:

Originally posted by sigfreund:
Of possible use to determine the size of the rail:
https://www.diproductsinc.com/Products.aspx?CAT=4268

If it is determined to be an 11mm dovetail rail, an Internet search for “11mm dovetail scope rings” produces results for several sources.

I was told by someone on another forum that 13mm dovetail rings fit perfectly on his 452 American. I need to find a place that has different rings so I can try them for fit before buying. Another variable is the dovetail's angle, 3/8" is cut at a different angle than 11 and 13mm.