Who gives a crap about FPE??? As long as the bullet has enough velocity remaining to expand properly, and enough momentum to penetrate through whatever lies between it and the vitals, I'm happy. Kinetic energy is a nice theoretical yard stick of how much potential work a bullet can do, but there are so many variables and factors involved in how that energy is used, that it is not a good measure for comparing the lethality of various bullets.
Secondly, 7mm bullets will give you a bigger bang for your recoil/powder consumption "buck", so to speak. Take two cartridges with like powder capacity, the 7RM and the .300WM. Fire a 180gr VLD in the 7RM at 3000fps, and the 210gr VLD in the .300WM at 3000fps, and tell me which one will arrive at 1000 yards with more velocity/energy. As long as the bullet retains 1800fps or more, it will kill cleanly and easily.
In order to gain anything in .308 over 7mm, you have to step up to a higher powder-capacity boiler room, so you can send the truly high-BC bullets faster than you can send the equivalent 7mm bullet. This means more powder burned, and a lot more recoil, neither of which I would suggest for someone who is just getting into LR shooting/hunting.
The 7RM is about as large as I would suggest for somebody looking to get into shooting sheep at 450-500 yards (or even 900-1000 yards), and it would be about perfect for a guy wanting to shoot elk/moose at that same range. If you start a 162gr A-Max at 3100fps, it should still retain enough velocity, depending on atmospheric conditions, to expand properly out to beyond 1300 yards, BTW. The 180gr VLD at 3000fps is more of a good thing. There are too many videos floating around of people killing big critters beyond 1000 yards with a 7RM for me to suggest that it's marginal at best.
Long story short, a Big 7 will give you "more for less" than a .300 Mag. If you want to shoot extreme distances (I'm talking about shooting at like 1200+ yards, here), you could step up to a .300RUM, or similar, to send those heavy, high-BC bullets at high velocity, but then you might as well just step up to a big .338 and enjoy truly good LR bullets, with enough velocity to make them really effective.
We need to remember that bullet weight is only one factor in calculating a bullet's BC value. It is not the final word in exterior ballistics.
Chin/Pseudo,
Get a 7RM or a long-throated 6.5x55, or something like that. It'll make for a lower-recoiling, ligher-weight rifle. That will make it more enjoyable (and cheaper!) to practice with, and it'll be just as effective as the .300WSM or .300WM when it comes to killing stuff (keeping in mind that 90% of killing power comes from putting a good bullet in the right spot, 8% from proper bullet performance, and 2% from the specific cartridge that you choose). For shooting stuff at 450-500 yards, you could make do with about any factory sporting rifle, chambered in any legal chambering, using a decent scope with a LR reticle or decent elevation turret. IMO, 500 yards is really not that far, at all.
