A caliber that I've just lately been interested in is the 7 WSM. Mostly because I want it to fit in the short action that I own and work with the 8 twist 7mm barrel about to arrive. From what I've seen thus far it's not a common or popular chamber.
UN-Fortunately, the 7mm WSM is almost, Obsolete and HAS been, Supplanted by, the .300 and .270 WSM's,.. in Popularity !
When my .270 WSM goes "South", I will Re- barrel / Re-chamber to, the 7MM- .270 WSM with, a 1-8.3 Twist, to shoot the 165's to 180's for, Elk.
.270 WSM Brass, Necked up ( NO Doughnuts ) with, the WSM length Neck is, a VERY accurate Cartridge that's, used in England and Canada for 1,000 Yard Competition. Hopefully, I can stand, the Recoil, LOL ! The .270 WSM with, 140 Berger's at almost, 3,200 FPS, IS, a good Elk Slayer, as IS, tho !
The longer/ Heavier, .284 Bullet, HAS "enviable" BC's for, the Longer Ranges and the .270, 140 gr. does,.. NOT !
I really LIKE, the WSM's, Case Design, Strength and Powder Capacity !