My eyeballs yearn for "tin hat" targets. As do my Enfields. Trying anything else but a 6 o'clock hold leads to the kind of target that will fall into two halves, left and right, if I shoot long enough. The vertical position becomes sheer guesswork!
:wave:
Newcastle, like Patrick says, military rifles need a Tin-Hat target.
Easy to staple a sheet of white paper over the lower half of your black target.
Most large fishing stores handle GLO-IN-THE-DARK fishing lure paint. It comes in chartruse and orange and requires a primer for maximum luminescence retention. I have sucessfully used it on several handguns.