I wrote this up for a friend and thought I’d post it…
The first thing to understand about the scope industry is it’s impossibly huge. There are WAY too many options. Given that I’d get something modest first to see what you like and assume you’ll get something else down the road. In my research it seemed the 3×9 (zoom) x40mm (front lens size) with a standard reticle (crosshair) was the most popular. From there I set a price of $300-$500 and from there narrowed the manufactures and models. Finally, take the list to Cabelas and try them all out. They’ve got almost all the scope models available for testing and even a stand so you can test them across the store. I bought from them too for the service of keeping the product in stock though it cost a bit more.
I bought the Leupold VX-II in the above specs for $299. It’s a very nice, very standard scope. I would buy something else knowing what I know now and given the opportunity to do it again for the AR-10, but the scope will be really great for a number of applications including hunting rifles or even plinking on a .22LR so I’m not disappointed with the purchase. It’ll get used A LOT for YEARS to come on many different guns. It’s probably a good start.
For the AR-10 Carbine I want to get an 4x or 6x ACOG next. It’s about $2000 so that’s a couple years down the road.
For the AR-15 I got an EOTech 512 red dot. Wicked cool but no magnification which is a bit rough. I’ll probably get a third party magnifier for it for around $200 which should round out the features. If you go for the EOTech go for the models with the adjustments on the side so they can be manipulated with a magnifier installed. The 512 has them on the back which is not optimal in that case.
Finally for the scope you’ll need rings. I went for the Armalite one piece set so the dis/mounting is easy. With two separate rings you’ll need a $100 mounting kit to make sure they’re in line and don’t break your scope. You may be able to find a cheaper one piece and definitely more expensive ones with quick release etc…
With optics it’s all about seeing the product before you buy. Narrow the list and take the family to Cabelas one weekend to look at all the models. Bring your credit card.