I replied initially to your question but if possible Id get another VX6 3x18 to put on the 6.5prc since the VX5 doesnt have an external windage dial. Then you could put the VX5 on the 300prc since it sounds like thats the rifle you will use the least, sell the Vortex.Thanks. That is what I have planned so far. I got the 300 PRC for Moose/Bear last year. And while I like it and it has been a great shooter, I can't see picking it up over the 7PRC right now. When I got to my moose hunt, my guide was telling me that most the natives that have been shooting moose their entire lives use nothing even close to a 300. He himself has been shooting moose with a .243 since he was a kid. The outfitter had recommended and wanted me to bring a 300 or 30.06 at minimum.
Side note I have two VX6 3x18s and never lost tracking. Friend has a VX5 and its a really nice scope too but his windage dial isnt the CDS. As far as moose caliber I dont see why a 7 isnt big enough but Ive never hunted moose but whatever a 7mm is fine.