I read with interest the post concerning the Danish 6.5x55 (intended for for Swedish 1896 rifles used by the Danish Army) that was condemned because the bullets left cupronickle deposits in rifle barrels.  This was supposed to increase pressures as more & more of the stuff was fired, as would be likely if military ammo was used as such.

In one of Phil Sharpe's monumental works, he wrote about shooting a 1903 Springfield at Camp Perry (early on, between the wars).  He detailed how his quite accurate National Match rifle suddenly became wildly inaccurate, which he blamed on cupronickle-jacketed bullets.  These were 150-grain bullets, issued before the 172-grain M1 match ammo was loaded.  Sharpe blamed the fouling on the high velocity (2700 fps?) ammo and said that at lower velocities, cupronickle fouling was not a problem.  IIRC, he made reference to issue Krag ammo not fouling.

I always thought that the pre-WW1 issue Krag bullets were cupronickle.  Is that correct? 

And was cupronickle fouling a problem with the Krag?

And would the bullets salvaged from the Danish ammunition be OK to use in a Norwegian Krag if you kept the velocity levels at about 1800 fps?