This one:
460 8 3/8"
I already had 45lc components and dies that weren't being used. I shot my grandfathers 44 mag with full power loads and my own cast powder puff loads, and liked it. I already load for 45 acp, so I had some molds an bullets for 45. I searched for bullets and found many more available for the 460 than the 500. I wanted an impressive, obnoxious, manly, gun that could also easily be tamed.
I have hand loads from 560 fps to 1917 fps. Last weekend, I loaded up some 230 grain LRN 45 acp bullets that I had lying around. 6 grains of red dot, inside a 45lc case, gave me around 650 fps. I was shooting at a 3/8" mild steel target from 20 yards. There was no problem with beating up the target, the loads had very mild recoil, and they were dirt cheap to load. My 270 SAA HP's, in the photo above, hit that steel pretty hard though. For light 460 loads, I use trail boss powder-cheap, fast pistol powders are not bulky enough. Trail boss would also be used in the 500 for light loads, but trail boss isn't cheap. 45 lc works great with the cheap powders. If you only shoot full power loads, then it doesn't much matter.
I shoot some medium and full power loads as well. I wanted a double action revolver of my own. I like high end products and the X Frame has an exceptional trigger and finish. My dad's 38 spl Smith is just kind of blah. The 45 colt loads are much more fun than 38 spl. I guess I am like the old guys that drive their fancy Corvettes down the freeway at 65 mph and only occasionally open it up.
Another guy made fun of me for not getting the 500. He has a 500 x-frame. I don't know what load he had, but it was punishing to my hands. The 460 in easy on the hands with a 240 grain hornady bullet flying at 19xx fps and being propelled by 45 grains of Win 296 powder. He was partly joking, but he also has to try and one-up people. I don't have to have the biggest..............................just the fastest
PS. My x-frame is purely a range gun, for fun. I don't hunt. A 45 colt 270 grain bullet would also work for home defense, if that was what I had at hand. If the size didn't make the perp crap himself and run, the round would ruin his day. It would double as a billy club, too. In reality, my XD 40 would be my first pic for home defense. I have 30k+ rounds through it and can handle it without looking at it, and can hit targets even without looking at the sights.