IIRC there are 5 different bolt heads for the SMLE to compensate over the life of the rifle......the 1917 is the same sorta setup as the 98 Mauser though and its a part of the bolt....
there is enough meat on a 1917 action that you can remove enough and still have plenty to run a 505 Gibbs.......i do know they are darn heavy for anything on a '06 case.....ive got a 1917 chambered in 338-06 that a 10 year old could shoot all day with minimal discomfort....
