Couple of other things you might want to know.

The groove depth on all 1905 other than the 1905 Mk II** is .0055. Groove depth on later models was .0042.

The Lyman No.50 was only made for a short time, and will only fit on 1905 actions. So although usually found on higher end rifles like the 1905-E, 1907-E and Scotch Deer Stalker, it will not fit on a M-10 .280.