COLT SMG UPPER RECEIVER OPTIONS

I like these sights Individually and they are a few of the most strong and nicely-built sights around for that AR 15. They feature a small and enormous aperture and over the smaller aperture there is a list of open up box sights for fast-fireplace shut-quarters use.  I have never decided on a flat top rated or A1 (with no FA and deflector).  I a