That group is even better than it looks and it looks pretty good to me. There was an intermittent breeze swirling mostly from behind us but unpredictably from the left or right. It wasn't anything like 33 mph gust, but it was sure enough to slide a bullet a caliber or so to either side.
Vance also got a five shot group with .38 Special wadcutters that was one slot just over an inch high. That's a lot of versatility in one rifle, and oughta pretty well answer the question of whether Maxing a Handi hurts accuracy with the shorter cases.