Since you said it was for your first AR, I'm assuming you mean like a basic multipurpose optic for defensive purposes and range use. Max ranges? As in fixed red dot or magnified scopes. Can also use fixed red dot with flip to the side magnifier.
Being your first AR I'd suggest getting an adjustable 1-4x or 1-6x, or Vortex just came out with a very good 1-8x scope. Then you get the best of both worlds. Fixed 1x illuminated reticle for close range or can adjust to 8x for longer ranges, easily out to 600yds. Might want to start out with a more budget minded scope and play around with it to get a feel for what you like and don't like, then if you want can spend the money on an expensive one if you want. Being your first rifle tho, you probably aren't sure what you want. Even looking for quality used ones to try would be good.
For what it's worth, I've used nice high dollar ACOG, Aimpoint, Eotech setups in the military then as a govt contractor and they were very good no doubt and best of all were FREE
Now that I'm retired from all that, while I could afford it if I wanted to, for my purposes now I don't need or use any of those now.
