I'm looking at accuracy and handling qualities as the measure of efficiency, rather than maximum velocity for any particular load.
You'd probably have to define "accuracy". Does that mean putting a fist sized group into a sillouette at 3 yards, point shooting in the dark? Or 1" groups at 50 yards, slow fire single action, aimed? Likely somewhere inbetween.
I'm as accurate, at any range, with my 1-7/8" Chief's Special as I am with my 4" Model 66. And for me, that means really good, "target" accurate. I can hit that center mass bowling pin at 3 yards with anything, probably with eyes closed.
I guess what I'm suggesting here is that for normal carry length bbls and ranges, I don't think there's much, if anything, to consider regarding accuracy.
Sgt Lumpy - n0eq