Wondering what optics you guys like on your AR's for 300yds and in while spending $350 or less(not including the mount). I'd love to shoot for groups at 300yds or more and still be useable at its lowest power at 50yds. Right now I'm toying with 2.5-10 figuring it would he plenty out to 500yds or something 1-6ish.

I had the Sightmark 1-6x24 on one of my ar's.  It works well and the glass is really clear for the price point.  I actually have it up for sale in the marketplace.  Only reason for selling is that I had been hunting for a more expensive optic and landed on the Vortex HD Gen II 1-6x.  For me the 1-6x scopes are great bc you can use em up close or still hit water bottles at 300yds if you want.  

 

Here is the link for it:

 

 http://njgunforums.com/forum/index.php/classifieds/item/1795-sightmark-1-6x-scope-in-adm-recon-cantilever-qd-mount/

 

If you didn't want the mount I would split it up, the scope actually came with rings I never used.