Spanish M43 La Coruna 1951, 8x57 ?

[vintage hunter]

It probably is in 8mm, they would have had to rebarrel it for something else but still advisable to take care.

Not necessarily. All that's required to convert an 8x57 to 8mm-06 is re-chamber the original barrel. Doubt it's been converted though but it never hurts to be sure.
Very nice example, BTW. Probably one of the best I've seen.