Interesting, I've always heard people say that the 2700 - 2800 fps range is a hunting sweet spot. I imagine that old saying has a lot to do with the performance envelope of classic cup and core style bullets.
In reference to your questions:
I've been told by my father-in-law that 3000 fps is the magic number but do you really need all that blast and power to shoot a deer or animal that size for hunting in pennsylvania?
No, you obviously don't need 3k fps to kill animals cleanly, people have been successfully killing animals with decidedly slower rounds for several hundred years. As far as I know, all of these previously dispatched animals have remained dead despite advances in hunting technology and the emergence of magnum rifle rounds.
And would it be worth me going out to buy one since I already have a beautiful customised winchester model 70 with a 6.5x20 leuopold on it and is by far my most accurate rifle I own.
Maybe I missed it, but what caliber is your Model 70 (I assume the 6.5x20 refers to scope dimensions)? If it is one of the cartridges normally used for deer sized game, and you don't mind taking it out hunting, I don't see why you would
need another hunting rifle.
On the other hand, if your Win 70 really is a strikingly beautiful rifle, or has sentimental value, you may not want to subject it to the wear and dings that hunting rifles tend to accumulate. In this case, a decent cheaper rifle chambered in any of the popular deer calibers ('06, 270, .308, 7-08, .243, .260 etc.) should serve you well and you won't have to worry about blemishing your custom rifle.
