I note the case length is the same for the 375 H&H and the 375 RUM (rim diameter almost the same - 0.532" vs. 0.534"). Can one use a 300 Win Mag R700 action and the same BOLT to build a 375 RUM? Thaks ahead of time for any responses - AIU.

Yep, may have to play with the feeding but it is an easy conversion

get a few rounds and see how they fit the magazine and how they feed up thru the rails.....I'm guessing very little modifications needed.

It should be little trouble. Getting the Remington M700 RUM box, follower and spring should be an easy snag from a parts place or directly from Remington. You might want to try their in-line straight stack detachable magazine fittings while you are at it. That would be really slick, and help with the rebated rim. That must be why Remington came out with the in-line vertical stack after RUM's were on the market for a while.

Yes it will work, but you will need a 300 Rum magazine and a 375 RUM follower and spring available from Brownells and some minor feed rail and ramp work. So minor you can do it yourself( just use swiss files not a Dremel). The Bolt/extractor sometimes will work as is, but should be opened up .005 more for smooth ejection.I would consider adding a second recoil lug or at least change to a good synthetic stock( HS precision) and steel bed the action and second lug. The .375 Rum is just at the point of recoil where these things become important.-Rob

Thanks for the info, guys! It's very helpful. Regards, AIU