I think the question is are you and your buddy really shooting competitive bench rest matches anyways?
I believe in 10 shot groups, and that's a fine one. But as the bench rest crowd says "its not your best group that's a concern its your worst". Its really hard to judge a gun by "best group" alone.
My point is, as a varmint hunter (.223 caliber is for/really). The groups posted by Handi shooters here are certainly more than up to the task of taking even the smallest (target) varmints at long range. Being able to "dope the wind", knowing the come up ballistics, etc. will all come into play more than any of the groups accuracy posted, for being able to hit a P-Dog or Woodchuck at 400 yards.
Last there are "two types of accuracy". 1) The most important to varmint hunters. Being able to place the first shot from a cold bore where you want it. 2) More important to bench shooters. Being able to group well after a few flyers, barrel warm up,etc.
For myself as a varmint hunter I am concerned with number 1 and in the case of Woodchucks, Fox & Coyote anyways I rarely have the opportunity to get a second shot anyways. With some tweaking & modifications I have been able to make my 22 Hornet Handi place the first shot from a cold bore where I want it, in various seasonal conditions, from shooting sticks,bags,pod, etc. to where I have confidence in it.
Your group is outstanding.
Question - If you printed a target with 10 Dimes or 10 Quarters on it. And on 10 differant days shot one round on each day, first round of the day each time from a cold bore, would you be able to hit each quarter or maybe even each dime at 100 yards?