Do the CZs have a integral barrel recoil lug? The ZKK has one, with a attaching screw.

Your "attaching screw" is loose.

Hows the Cub?

Doing fine,just fed the little fella and going to tuck him in tonight. He's excited that tomorrow is Christmas.

I know the CZ550 magnums do, just like the Brno602's used to.

Provided more consideration for when I bedded my 375. Used Acraglass behind both the action lug and the barrel lug and seems to have worked - may have been lucky though. I'm yet to do the same for my 458.

Oh yeah, almost forgot, the contact was not equal on both lugs on the original stock - the barrel lug was making contact while the action lug didn't.