I own an Aimpoint that was made in the late 90's that I got from a friend that had it over in the sand box.
I don’t know the model number but I have had it on several guns from an AR, Contender 44 mag and now on a Beretta storm carbine.
The comp M4 has no magnification so every thing will be in focus no matter how far it is from your eyes. That is one of the main advantages of a red dot.
The other is that it makes it very easy to shoot with both eyes open.
My suggestion is to go to a gun store that sells Aimpoints and hold it in your hands and see if it will work in the ranges you need.
I personally feel that the Aimpoint is the finest non magnification optical device on the planet bar none.
