Isopeura,
I agree with the main thrust of your post, put these Ruger cartridges are fantastic at breaking the CRF and H&H length action premium that we've been forced to pay for many years. Recently Remington addded the 375H&H to the SPS line ... why has it taken so long and why have we been paying almost $600 extra to see a 0.375cal barrel and H&H stamped on it when the Remington/Savage/Howa 'magnum' bolt faced actions are all H&H length??

The Ruger RSM in my opinion was brought to market as Bill Ruger wanted to see the 416 revived and selected the 416Rigby over the 416Taylor ... its a heavy action and way too expensive in 375H&H ... especially in Australia. If Ruger introduced the 505Gibbs and/or 500Jeffery ... then the RSM would have a purpose.

The Ruger cartridges also bring to market a lighter/trimmer package then has been seen before, its a good concept!
Cheers...
Con