I agree with the one or two other people that have already said it, but in that price range you can't get a decent scope that is going to be FFP. IMO I'd go with one of the fixed power SWFA MRAD scopes in that price range for a rifle like that. IMO, the next step up would be an SWFA SS 3-9x42 FFP, but it's $600. You can also get a FFP Falcon Menace scope for a reasonable price, but the durability is not going to be anywhere near as good as the SWFA's. IMO the SWFA scopes are about the best you are going to get for a tactical rifle if you are on a budget. You can get better scopes from Nightforce, S&B, Premier, USO, etc, but they are double to triple the price and not double to triple the quality.
That said, it really depends on what you are doing with the rifle. From the sounds of your post if what I'm thinking you plan to do with this rifle is correct, 98% of the scopes suggested in this thread will be a waste of money. If you want to hunt especially at short ranges as in 300 yards and under go with a Burris, Nikon, etc. IMO after having several of the $2-300 range scopes, the best of the budget hunting scopes is Burris, but others like other brands as well.
However, if you want to shoot long range, or purely target shoot, you don't want any of those. The BDC reticle is a joke, and more of a gimmick for people that want to think that they can shoot long range, but never really do and have no idea what it takes. What you want in a long range scope is repeatable turrets. Mil/Mil also makes things much easier. I personally like the 3-15 power range or 4-16 and feel like it fits nearly everything perfectly as it's a good do it all scope. However, that will also be hard to find in your budget. My advise is to check out SnipersHide.com and read up on there. If you want to read about successful long range shooting, that's the place to be and you will notice that it's very rare that you see anyone there with a Nikon sitting on top of their rifle.
