I have a carbine that still has the carrying handle, i have been looking at getting a nikon optic. i still wanted it to have an iron site, so i was looking at flip ups. but then i looked at the top of the handle. it has a hole in it, is that so you can put a rail on it? i know it would look kind of goofy, but i really like the handle sites, have them zeroed ot a T, and would save me the money of buying new sites.