Something I learned while down in Texas.
If you find that the reticle in your ACOG blooms too much when shooting in direct sunlight, try using shooting glasses with polarized lenses. I was kind of amazed at how much it cut down on reticle bloom in my scope, as well as the bloom on the fiber optic front site of my pistol.
That said, if you don’t have polarized lenses in your shooting glasses and want to reduce the bloom caused by the fiber optic strip in the ACOG, you might pick up a Scope Fly. I’ve been using one of these for a couple of years now, and find it tremendously useful.