Now that I’ve shot off a pile of Norma, Igman and Belom for the brass (did have fun though) I thought I’d look into the bore size for bullet choice. Couldn’t find anything on the internet, so I slugged the barrel. .3105". The slug fell through the mic at .311" and wouldn’t go at .310".
Thought somebody would like to know that.
Have reloaded some with Berry’s plated 123gr. Pushed them tp 2K fps and they’re okay, but accuracy is lacking.
Any other .310/.311" bullet is stupid price, so I’m contemplating a Faxon barrel. Talked with them and their 7.62x39 barrels are .3015" at the lands and .3085" groove to groove. Perfect for 308 bullets.
Welcome to the forum @ColloRosso 
welcoem aboard @ColloRosso perhaps @Josiah_PSA can fill us in on these specifications you’re asking about.
@ColloRosso thanks for the info on barrel diameter.
I was looking for that info too.
Would be interested to learn what you end up with, I am considering casting my own at these prices.
It IS a challenge, If you can get primers at 0.07 and powder under $50 a pound you are still really left with Hornady Bulk (250 count) 7.62mm .310 Diameter 123 Grain FMJ 250 Count
by HORNADY BULK BULLETS that can be found at 0.27 giving you and end cost of 0.54 per round.