Wyo. Coyote Hunter:
I never used a case filler with the reduced loads. Two other powders I tried were SR4759 and Hercules (now Alliant) 2400. The 4.0 gr. Unique/40 gr. jacketed bullet (which I later upped to 5.0 gr. Unique) load performed very well on small game. I go for head shots if I can, but I did punch two squirrel through the ribs just to see what the result would be.....just a bullet hole in & out with NO bloodshot meat. In fact, in the fall of 1990, I took my turkey with that load; the bird was at 50 yards and was starting to run off. I hit it right where the wing joins the body. The turkey dropped right there, and meat damage was negligible!
Screwbolts:
I would tend to agree with you on the difference in rifling twists. Two twist rates for the .222 I've seen used in various reloading manuals are 1-in-12 and 1-in-14.