A 7mag would not be my choice. A 375 HH would do quite nicely.
A 7 Rem. mag. with 175NP's will out penetrate a 375 with 270 grain!! I've seen this myself numerous times!
A big bear needs to be broken down and a 7 mag. with 175 NP's will do it every time!! All you need is an expanding bullet that will drive straight and go deep preferable all the way through....
As a matter of fact, a 30-06 loaded with 200 NP's will also do it every time, and when i was hunting big bears a lot, that was my min.. gun/load that i would use...
Yes i've went into the brush after a bear that was already shot with that combo...
DM