Passport,
Good snag. Have a M70 XTR Fwt Swede myself and a couple other 7x57's so I resisted temptation on that one.
Unfortunately, the 7x57 and the 6.5x55 are critters onto themselves for loading data. My extensive use of the two cartridges justifies Quickload in and of itself.
QL and a Stoney Point OAL gauge are your friends. Maybe shoot a box of factory fodder for a brass source and for comparative chronying of loads. Make sure to measure the water capacity of your spent casings and plug into QL for good data.
Get a back issue of Handloader Apr/May 2007 where Barsness discusses loading parameters for the 7x57.
FWIW R15 works as well with 120 TSX's in my 7x57's as in the 7mm08. 4350's dance nicely with 139 SP's.
However your chamber geometry will dictate ...
GE
