howdy!
I just checked my Remington-made rolling block actions and tang screws and am sure they are standard 1/4"-28 threads.
I checked a Spanish (Oviedo) action and it fits there too.
The Swedes were still heavily dependent on Imperial English standard tools and hardware in the late 1800's when your RRB rifle was made under Remington license. It's a safe bet that it was copied accurately to Remington specifications.
HTH
John