"To get decent at prone, I laid and dry fired my AR for at least an hour every nite till I got to where my muscle memory was good and things got better."
Well that's certainly one way. Most people I know only dry fire offhand, or maybe a little sitting. They take prone "for granted."
I also perceive that you probably have excellent vision and are not a big fat guy. That AR15 is too small to fit me well and, after shooting the shorter ranges all day, it's hard to see that close front sight. Of course, I tend to dwell on it too long before firing. A few years ago I could actually shoot a tighter "cone of fire" at 300 rapid than 600, because in rapid I don't admire the sight.
