Deleted
Put electrician’s or duct tape on all but 1/2" to 1" of the fiber optic. Play around with it and add or subtract tape until you have enough on to allow only as much light as you need to use the reticle.
In full lighted conditions, the ACOG fiber optic generally allows too much light to transmit into the reticle, causing the chevron and the uppermost vertical red (or amber, or insert color here) line of the BDC to “bloom” in the manner you are seeing. The lit portion of the reticle is both fuzzy and appears about 2x larger than it actually is, meaning that you’re unlikely to be actually aiming at what you think you are.
It’d likely be the same with a horseshoe reticle, given that the fiber optic is no different on those models. So, tape it up! I’ve actually painted over mine, so that in full daylight, it’s still crisp, and during dusk, the tritium carries most of the weight, with some ambient to help out.