This is weird, I am replying to my own post
. After I posted, I looked up the7 LRM.
The first thing that came to mind, is that the 375 Ruger is it's own creation, and it dosen't have a parent case, as does the STW. IE, 375HH, 300HH, 8 mm Mag, etc. That all being said, IF the Ruger cartridge dries up, find brass for it could be tougher than finding STW brass. The STW's brass can be made from a number of 375 HH family brass, simply by fire forming, or other forms of case forming methods.
I am not aware of it's ballistics, or capacities, either but would tread lightly, or at least consider the possibility of the brass issue.
Besides, there's a little " magic" that goes on with a STW, that until you own one, and load for it long enough to realize it. But that's just me,and I could be guilty of being a little " prejudice".
I know of few guys that are shooting 7mm 300's, and nearly getting the speed the STW delivers. The deer dont know the difference.
Just a little food for thought.