I am battling the same issue with my new SAKO FINNLIGHT
300 WSM. I must seat at least .175" back from lands (measured with Stoney Point OAL guage) to barely clear the magazine with 180 nosler partitions. This still, by the way, greatly exceeds the SAAMI from Hornady manual.
Assuming rifle range testing proves my plan acceptable, my plan is to load my "chambered hunting round" cartridge to .050" back, then have 3 backup rounds that fit the mag.
WHO HAS A BETTER SOLUTION?
I got a big Alaska moose waiting on me in a couple weeks, and I want to be ready!