The big difference here is two countries and two (or more) different types of actions. The Norwegian Krag is probably slightly stronger than the US Krag in some ways and some models are weaker in others. The European Krags where built with the bolt handle bearing on the receiver as a second "lug" not as a "safety lug" as the US Krag. The Model 1894 Norwegian action had right angles milled in places where the US and 1912 series Norwegians had "curved" millings. The square millings can be more prone to cracking. Even the strongest Krag receiver is not as strong as the weakest Mauser type receiver. Sweden produced ammunition for the stronger Mauser action Model 1896 and later the Ljungman and can be and likely is higher pressure. It is not worth the risk. This is not so much about shooting older ammo as it is about the origins of the older ammo. One other point is the OP asked if it was "safe to shoot", we all need to be very careful how we answer those type of questions due to liability issues.