Tino- I'/d go with Bonanza's suggestion on the .50 Sharps 3 1/4" rather than the long .450. The reason for this is reduced pressure with loads that will get the job done. As well, a long .50 is generally easier to find good accurate loads for than a long .45.

With a .50, you can stay beneath 36,000PSI and still get well over 2,000fps with a 520gr. bullet.