My eldest son struggled with flinching for a long time. Even a 22 would make him jump... What did I do? I got him really good hearing protection. It worked well. Noise is worse for flinching than recoil is (in my opinion)
Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull.
all 25 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple