I remember one time I had a G29 and it would shoot good but tried some plated in it one day and it was terrible but in a more traditionally rifled barrel, it was fine, so perhaps that bullet and your G22 don't get along, it happens. You may already do it, but before you shoot live rounds, sit and dry fire at the target for a bit to get the feel of the trigger down pat instead of going at it cold turkey. I recommend a firm grip (think firm handshake), too tight can be just as bad as too loose. You're accustomed to Glocks it seems, just I'd recommend just dry firing a bit at the target first, firm grip with a slight push from the strong hand and slight pull from the support hand and always bring back the trigger to the trigger wall (short reset point) before firing. Looks like from earlier posts it shoots factory ammo pretty well.