Beautiful rifle and good shooting.
I see you have a Kepplinger trigger; have you tried shooting the rifle with the trigger set, and unset? I find that sometimes, some of my rifles shoot just as well, if not better when unset. Hard to figure, but may relate to the increased lock time and "bump" of the trigger when set.
Also, did you put a lighter "speed hammer" in the rifle? This will almost certainly shrink groups a bit, and certainly won't hurt your group size.
I'll defer to Steve Durren on the fore-end inletting advice. I'm sure he mentioned that the amount of pressure/contact at the fore-end/receiver face can be critical. A few thousands space between the fore-end and lower receiver "extension" can often solve a lot of frustrating flyer issues.
Good luck. A rifle of that quality in 222 Rem. should be shooting X's on a regular basis. ;-)
