Shu,
Welcome to the site. I've been shooting the 50 AE in a bunch of different guns, Desert Eagle, BFR, T/C Encore, and Freedom Arms. It is a great caliber. You have the flexibility to shoot pretty much what you want in the FA 555, BFR, and Encore, cast and jacketed. I've had great luck with both. I shot bullets from 285 grains up to 440 grains. The real question is "how much is enough?" Most of us will never shoot at anything larger than whitetail deer or hogs. The 50 AE is more than adequate; and, it can be loaded so it doesn't beat you to death! It is another of the "great, ignored" calibers. If the price is right, GO for it! I have never had a problem with the bullets "walking" with a tight taper crimp. Check the data in the last 2 Speer manuals. They give data for jacketed and cast bullets in the FA.
Doc