After much debate on an optic for my new varmint rifle I decided on the Nikon P-223 3-9X40 BDC 600.
From the Nikon website: http://www.nikonsportoptics.com/en/nikon-products/product/null/p-223-3-9x40-bdc-600.html
Developed specifically for the trajectory of the .223 Rem /5.56 NATO round...
Recommend a good 2.5x scope for the AR-15.
I have an AR-15 that I am going to be using around the farm for wild hogs, coyotes,,, and the such. My longest shots are probably going to be around 100 - 125 yards, somewhere in that range.
Price is a factor. So please no $500 scopes.