Re: Which Low magnification optic for my AR
I have the millett, and use it for 3gun also. It's a great scope for the money, but the big drawback is size/weight.
The glass and reticle are worth the money. I have no trouble ringing steel to 400y (10") and sometimes 500y with crappy ammo and a 16" barrel.
I have mine on a uber lightweight AR and it's just way to big/heavy. Keep in mind that for the last 3 years I competed in the iron sights division, so I'm not used to the weight of a scope at all on my 3gun AR, but several fellow shooters have remarked the same. It seems to throw the balance off on my little AR.
I know a couple other guys that had the millett on their guns and they are fine, but theirs were 18-20" guns and were generally quite heavier. Both have upgraded to new, higher priced, scopes and are happy. They were generally happy with the Millett, just managed to scrape up the cash for new glass.
In your price range I think you might be able to afford a little better scope for your needs. I'm not trying to discourage you from buying the Millett, it's a great scoppe for the money. $600 is a decent budget but might be just out of the range of some really good glass.
I have my millett mounted in a burris AR PEPR mount:
http://www.midwayusa.com/viewProduct/?productnumber=199560
which so far is fine..but I've only shot 2 matches with it. You might be able to save a little money on your mount and spend it on the glass. I'd rather skimp on the mount and upgrade later than do the same on your optics.
Best of luck.