Need? Two. I want iron sight backup with even the finest optics. Prefer? Three. That red dot Docter is perfectly visible through the M16-type sight channel under the scope, and is zeroed in for 50m, which is basically point-blank on this rifle. Besides, my eyes need all the help I can give them.
Not a bad idea.
I don’t have the rail space on my ARs, unless I replace my rail system with a same-plane rail. LaRue Tactical makes optics mounts that now allow for a secondary optic to be offset from the main optic at a 45 or 60-degree angle. Usuall a small Aimpoint Micro on a target/tacical scope.
Is Docter still making sights? I thought then went out of business about 8 years ago, and everybody else is now making copies.