I have a buddy That has an AR-50, he is looking for a scope and not wanting to spend a lot at the moment. I have been looking at the 6-20X50mm PST Vortex for $279 for him. I was wondering if this scope can with stand the muzzle blast of this rifle, and also the quality of the optics, tracking,clarity, and durability especially mounted on the .50 . I know there are probably some better choices for a few hundred dollars more but he is not wanting to spend more than 400 or 500 hundred dollars. Any comments appreciated.