When considering cameras like that remember it doesn't have a 500mm lens,they are talking FF equivalent,the actual lens is about 185mm,as far as 1 inch sensor cameras go a better bet if you have the Nikon 70-300 like you do is something like the 1 series V2 and FT1 adapter,you would end up with a equivalent of 189mm-810mm.
These where taken with the V2 and 70-300