I have been shooting a .22 (G44) quite a bit lately. I am pretty astonished at how much better I shoot this gun compared to my carry G19. When comparing hit factor on several drills, my HF with the G44 is around 50% better than my best with a G19. That is nothing to sneeze at.
I think the improvement comes from several factors:
1. Shot to shot recovery is much faster. Sight tracking is much easier.
2. Less beating from the recoil/blast leads to less recoil anticipation/flinch, plus I can focus carefully on trigger fundamentals without flaws being hidden in the recoil cycle.
3. I can shoot a lot more in any one session without getting overly fatigued which leads to more learning.
I have generally poo-pooed the importance of the gun in a shooter's performance. For most off the shelf service pistols, my performance is within a few percentage points if it is even measurable and not just random "noise." The difference in my performance with a rimfire is measurable and undeniable, however.
This has me thinking of the usefulness of things like the "Roland Special" or the STI gun with the comp. I had previously thought these things were gimmicks, but now I am not so sure. If I had a 9mm that recoiled like a rimfire, would not my shooting performance improve significantly? I guess there is a reason for open guns run in a different category in competition.