Unfortunately anything in OK over .45 is illegal to carry, so .454 Casull (only .004 over), .460 Ruger, .50 AE, .50 GAP and 500 S &W would be illegal. I would imagine with the .500 though you wouldn't have to pull the trigger, someone would have a heart attack staring down the barrel of it!It is definitely a gun for the guy who loads his own. I run mine with 350gr XTPs at 1500 fps, and it isn't bad at all. It's a fun gun to shoot. I wouldn't want to have to carry it on my hip. I'd probably walk in circles.
As for the .500 no desire to shoot one. I'm not a hunter and currently there isn't a major Raptor or T-Rex problem in Oklahoma, all though that could change.
I would imagine though the .500 would be a great implement for those that hunt or need it to protect themselves from bears, There are those that hunt bear with .357 mag, however I would think that would be a little light.