ll I know is, after I got a new (Larger) hinge pin and started using fired and minimally-sized brass, my .223 started shooting tiny groups. So maybe I should've said "minimally-sized."
Here's another question--if headspacing is critical, why wouldn't you want a crush fit?
I don't think my sample of one necessarily proves anything, but you could say the same about your sample of one, especially since your handloads had been sized for a different rifle.
