Anyone got one of these,that they would not mind measuring?
My little Brno gal is long gone but I dont remember what I measured the bolt dia. at the forward section to be....

Measured it at 0.580" just forward of bolt handle where there is a full diameter and also same across front near locking lugs.

This is a nominal measurement and it varies from about 0.575" and up depending on exactly where you measure it.

Why do you ask? Have a project in mind? I have seen this action used with cartridges based on .222 and .223 etc.

The later BRNO Fox models were/are offered in .223 as well as the Hornet.