So i went to the range the other day with ~500 rounds of .45ACP to put my new XDM 45 3.8" through her paces for the first time.
I started with the correction targets for the first 400 or so rounds, then two silhouettes for the last 100 rounds (50 or so each).
These targets are ~75% size (printed on 11x17 paper landscape stacked on top of one another) and were at a distance of 21 feet.
I took my time to try to do everything correctly even though i had a few fliers, but my groups were consistently low (more apparent when transitioning to headshots for 2 and 1 drills).
I know its me and not the handgun 
.
Can you guys give me some things to check for the next time i go to the range. i have a feeling i may be dropping my head or not adjusting POA, just dont have enough experience to know which it is.
I cant post links to it or embed it :*( but groups are consistently center, just ~3-4 inches Low (hitting adam's apple and belly button, aiming between the eyes and center mass/heart)