Interesting, I find 9mm from a Glock 19 very easy to shoot. I definitely have less tendency to flinch than with a 1911A1 in .45ACP. One reason I chose the G-19 for carry was that it fit my hand and was so easy to shoot well. Maybe it's the 147 gr Gold Dot ammo.

I agree wrt shooting lots of .22. I bought a Ruger .22/45 and would shoot two boxes of .22 and then two magazines of .45. .22LR groups were very tight -- .45 not so much.