All depends on what you want and what you'll use it on. If you decide on a single shot, there is NO load made or can be loaded for the JRH that can push a 400 gr bullet to 1,900 fps like I can in my 12" 500 S&W SSK Encore Barrel. Just depends on what platform you want to use.
David, my buddy (who shall remain nameless) got 1,650 out of a 440 grain bullet and a 6 1/2-inch barrel -- with a barrel gap, and it fits on your belt. For a revolver, a packable, useable revolver, the .500 S&W isn't a great option in my humble opinion. When I determine I need more velocity, I'll move up to a rifle. The whole premise behind "handgun" hunting -- at least for me -- is working within the design parameters (actually limitations). I accept the fact that I will not be able to achieve rifle-like velocities with my chosen tool, and attempts to do that compromise its effectiveness. With that, I have bullet diameter and bullet weight. If my penetration is adequate, the only issue is placement.....