With your firearm restrictions, yes they would be about the best option for you for longer range shooting. Still, I would recommend a heavier bullet for better consistancy.
I have shot alot of big game with handguns and I can say that for me, I limit myself to 125 yards when using a revolver or even single shot like the encore when chambered for traditional handgun rounds.
The reason is that is as far as I can accurate place the shot into the vitals from field shooting positions. That is a critical statement. Off a bench, 200 yards is very practical with a good handgun scope, over your knee from a ground blind or off any other less then solid field rest I limit myself to around 125 yards.
On game, you will be much more impressed with a 325 to 360 gr bullet. Recoil is pretty high with these bullets so you may want to consider using the Speer 300 gr SP Unicore. It is a great bullet and will serve you well in the big 460 and will be a great performer on deer size game at any velocity you push it to.
I played with the high velocity loads many years ago and learned quickly that a heavy bullet with a large flat on the nose will kill just as if not more effectively then any high velocity bullet.
That would be my recommendation.
Please keep in mind that this level or round will have signigicant recoil. I have a 454 in the Encore and it is the only handgun I have ever shot that physically HURT my hand to shoot. That was with a 300 gr pill at 1700 fps. Now you will be able to pass this level of performance easily so remember that recoil will be impressive. If you think you are recoil proof, running several rounds though one of these monsters will really put you to the test.
For deer, and my self imposed 125 yard range, anything from the 44 Mag, 45 Colt and 454 will work just as well as the 460 and will be easier to shoot.
Again, take this for what you will, just another opinion.
Kirby Allen(50)