The M96 action is considered less strong than the Mauser 98 action because it lack the 3rd "safety" lug on the bolt, and does not have the same features for deflecting gas from a ruptured case away from the shooter's face. The "safety" lug on the Mauser 98 bolt doesn't actually do anything (it does not bear on anything in normal use), it is intended to keep the bolt in the rifle if the regular front locking lugs completely fail.
Swedish steel in those days was considered to be the best around, and their machining is first rate. However, the metalurgy of the early 1900 era was not as good as it is today, and the safe bet is not to hot rod these fine old rifles. it just isn't worth the risk.
Good writeup.
Ludwig Olson, the author of Mauser Bolt Rifles, wrote an article, I forget which magazine, and stated that the Swedes used the same plain carbon steels throughout production. Even though the design is strong, and the 1940's metals vastly more uniform, cleaner than 1900 steels, plain carbon steel is still a low grade steel. Plain carbon steel has a high varibility in hardening. Some shallow, some deep, within the same heat treat. Alloy steels harden evenly, give higher yield and ultimate values, and are used in every modern western action.
So what I am saying is, as good as the action design, the metal may or may not be that good, even the late ones. Stick to factory velocities and everything thing will be fine.