The Standard Mosin Nagant rifling consists of the following: The barrel is a 4 groove, right hand twist, with a 1 in 9.5" (24.1 cm.) twist for all models except the M28/30 which is a 1 in 10" (25.4 cm.) twist.
M28/76 should be the same as the M28/30 since they are built around the same frame and barrel. Information of the other Finnish rifles still needs to be checked.
Seeya
Mark