I am new to precision shooting and bolt action rifles in general. I have a Remington 5R in .308 and am considering the Vortex PST 4-16x50 or 6-24x50. It will be a dual use target and hunting rifle (mostly target shooting out to 500 yards for now). Which of these optics would be a better choice and can you recommend a picatiny mount for this rifle? Would there be a better optic for the same price? Does the Razor HD 5-20x50 justify the extra 1000?