ORIGINAL: Pygmy
Just for conversation's sake, regarding using a relatively fast powder in a big belted case... I saw a young fellow set up the bolt on a .300 Weatherby one time...Gas rolled out of the action and he had to hammer the bolt open with a block of wood... He was using a manual published load of 3031, which would be a real fast powder for that case....
Has nothing to do with fast powder. Same thing has happened with me with RL25 and 300RUM. Its the amount of powder you use and did a person work up the load.