I'm looking for a decent scope to go on a 18" BCM SS410 upper. I'm on a budget, and can get this particular scope for 299.99 shipped, new. Everywhere else I have looked, it's 400+, usually around 470.00. 

Anybody have any experience with this scope? 5-600 yards is going to be the max distance this setup will see, mostly under 500 though. I'm wanting a decent, clear, reliable scope for around 300 bucks. And so far, this seems to be the best choice I have found.

For the price they're decent little scopes. I had the mil-dot reticle version on a 223 for a while and it did well with the paper punching that I used it for. Image quality/resolution were pretty good. I later sold it to my buddy who has been running it on a lightweight 270 for over 300 rounds. He still has it and has zero complaints with it loosing zero.

Only things I didn't like about it were the short eye relief and that the mils were set at a weird spot in the magnification range, like 14 or so. Since you would have this mounted to a 5.56, the eye relief would not be an issue.

I have/had that exact scope.  Just sold it to my Brother.  It's a great scope at that price.

I used it on a 20" 5.56 out to 300yds on a regular basis.  The holdover with the BDC at 300 was great with 69 and 77gr but I can't tell you anything past that.

The eye relief gets real tight above 16x or so.  That's really the only complaint I had about it.  The clarity was good and the high end of the magnification was nice at 300+.

If you want a scope with that magnification range you probably wont find anything as good for $300.