Which Scope?

[samnev]

For that price, go with a Leupold. Their warranty make them an excellent purchase. Customer service at Bushnell is terrible, and Nikon's is not much better.

I agree Leupold if you can afford one, As For Bushnell i've always had excellent service from the, My brother has a Bushnell 3200 Elite Variable, don't remember the magnification range, that is an excellent scope that's in your price range.

 

[batmann]

Although it is only a 3X, I really like my Burris AR 332. Comes with a mount, has a BDC and will go green, red or black with variable brightness levels.

 

[RDFabsRep]

On one of my guns, I have a P-223 (3x32) in an American Defense 1-piece mount. It's rock solid--great shooter up close, or a little further out.

For a different setup (but still similar) I'm leaning towards a Tac30 and a Larue LT104 mount. Again, good for up close and even further out, but the retical is a bit fatter than the crosshairs on the Nikon.

Both setups are within your price range.

 

[Kodiakco]

On my OR I have the Burris Fullfield E1 3-9x40. It has pretty good glass for the price. I also have canted BUIS for close in.

 

[Lman57]

I like the Nikon P-223 3-9x40 on my AR-15.It has bullet drop compensation out to 600yds.Several others on here will also attest to the quality of the Nikon.It was my first purchased scope based on video and online reviews.It works so well that I found no need to look further.
You can spend a lot more and not necessarily see the benefits for your usage but this is solely my opinion.

55gr ammo is what I use and have no problem with it.

+ 2 I use the same scope works great.