is a straight top action, the only thing you will need to be concerned about is the diameter of the picatinny base. I don't recall offhand what the diameter f the M action is. I know is is bigger OD than any of my S actions. base your search on the OD. Or you can take a couple of passes with a fly cutter and the use a flat base.
David
From my notes, the Hall 'M' is 1.500 diameter. The bases used the common .860 hole spacing and #6-48 screws. Kept notes on this one as it was done as a bolt-in with a lug, not a glue-in.