I have access to an as new Zastava rifle in 300 Win Mag the action I can use for a rebuild

I have also got a 458 barrel blank that measures 1.200 at the chamber end.

My question - is this thick enough to tap and screw into the Zastava action or do I need a barrel with a thicker shank like 1.250 or 1.300

regards
Short & Fat

It is the same as the 98s. 1.1"

1.2" will work fine.