JUST CURIOUS . . . WHY OUT TO 500(+) YARDS?
You can dump a pot load of money into your gun to make it "match grade". Don't need to . . . but you can.
I could go down a list of suggestions but let me stear you to an outfit that "specializes" in long range shooting/hunting.
From a TV show called "Best of the West", http://www.thebestofthewest.net/
There are DVD's of examples of long range shooting, and a "How-to" DVD of how to achieve successful LRS by modifying your gun. Like pillar bedding, floating the barrel, etc. VERY good stuff! Look for their Video Archives for some sample shots. In their Store, there are DVD's called "Beyind Belief". And they are! Seeing still won't be believing! They take an elk at over 800 yards with one shot. They also caution you from trying any of what they teach until you have become very good at the practice range. Ethical shots first!
If you want to shoot long range, these DVD's will help you do-it-yourself.
I don't think you need a $1,000.00 + scope, but it is very advisable to get a better scope than you have. And...........
One that has features you can use like interchangable turrets and higher power.. Example: http://www.cabelas.com/cabelas/en/te...amp;id=0043015

It's a long link, but try to get there. Cut & paste.