What is the velocity bullet in a barrel length of 22' caliber .460 weatherby ?

Answer.... plenty fast and with a good fireball to impress your freinds. Seriously, mine is 26 so I don't know but the Pendleton brake gives some pretty cool side blast.

for a 500 gr bullet? it depends on your pressure, but I would estimate between 2300 and 2400 at FACTORY loads

Alain... I reload, shoot and hunt with Matts(he posts here on occasion) 22 inch 460. I can get 2500-2550 with a 500 grain bullet safely... I doubt you could go much beyond that. Matt mostly shoots it at 2400. I am not sure what the factory loads chrono at but jeffe is probably right. His rifle is a cz550 in a mcmlln stock. Its a great rifle and for the life of me I dont know why more people who reload and choose a full size 550 dont make one in 450 rigby/dakota or a 460 wby when looking for a 458 caliber.