Thread: Cartridge advice 2.0 - the 7mm version

Can't help you with some of your questions,
I would hardly suggest that the wsm "is on the way out" the 7mm 300wsm was never huge and wouldn't be my first choice anyway.
The WSM case in itself is certainly not going anywhere, if you did you go down the wsm route I would suggest a standard 300wsm as it is far more popular and factory ammo whilst expensive is available.
Brass in standard wsm cartridges (270wsm/300wsm) is definitely going to be available for the foreseeable future.
Whatever you choose I would be cautious about any cartridge in 7mm/284 in the current climate as pretty much anything 7mm is almost impossible to obtain.
I suppose things in the supply chain will settle down eventually.
Of all the calibers suggested probably the most mainstream would be 7mm rem mag and probably the easiest to get factory ammo, and having owned one they just work and there are some pretty sweet semi custom rigs able to be bought off the shelf in this chambering without the need for a full on custom build.
As far as reloading well that's a whole other rabbit hole, but for a learner I would suggest that buying/building something that you can buy factory formed brass for would the best option.
Anyway it's all up to you in the end and variety is the spice of life.