Free: Contests & Raffles.
If money is no object and 0-500 is the goal then I'd do this in a 300 win mag (OP's caliber)Lone peak razor ti actionBenchmark Ibex stock or manners eh1Triggertech diamond triggerHCA carbon barrel cut to 22"Light weight suppressor (im not versed on can's)Top it with a quality scope in an appropriate range (I am digging 4-16's right now)
I would say a good bolt action rifle in any cartridge between 270 and 30 caliber, topped with a 3-9 power scope and total weight around 8 to 9 pounds would do well in the vast majority of situations. It would not be the perfect rifle for every situation but no "all around" rifle will be.