build me a 500yd ruger light rifle, 10lbs

[RUMLUVER]

The 6.5-06 is a real good choice in two fold 1st like you said a good action to build it on is readily available and 2nd you have greater selection of bullets. You can shoot anything from screaming fast varmint wieghts to a well constructed game weight bullet. I would suggest for a game bullet using the Swift Scirocco 130gr it has a BC of .571 this is the bullet I'm basing my .264 Win Mag custom project off of. With the 6.5-06 and a 24" barrel you would be able to push this bullet at 3000+ plenty flat traveling there. One thing though if you go this route have your gunsmith throat your chamber out a little more than standard about .180 so you seat these bullets out a little farther. Just my opinion thats all hope this helps!