Tbitty
AH fanatic
Pardon my interruption, but I think you're going the wrong direction in pursuing open sights. Just forget the sights, and pony up a few more bucks for a Nikko Stirling 5-25x50 scope for precision shooting off that back porch. Mount it with the highest rings that you can find. If you're worried about the scope hitting your eye, then follow that suggestion to get a PAST recoil pad; but glue it to the back of the scope, and cut a hole you can see through.
Goat Guns Mini 16X Scope
Elevate your Goat Guns collection with the 16X Mini Scope. This 3-inch accessory is designed for seamless integration with your AR, M16, .50

Here's a good scope for less than the open sights would cost. It sits farther forward to help prevent the Scope Bite from too much recoil to handle.