Recently picked up blue label glock 19 and glock 43 couldn't pass up the deal. I have no trouble shooting sigs and can easily knock out bullseye 10-15yards out. I installed Trijicon HD's on both my Glock 19 and Glock 43 and went to the range to test these out. Both my 19 and 43 shot extremely low for me. At 7-10yards some were off the target completely of a torso size target. I had to compensate but aiming way high and even then i had no good groupings it was all over. I was completely shocked. I've heard glocks handle differently but to go from knocking out the red in the center target with Sigs and to not even land on paper with both the 19 and 43 what could be my issue? I have torn apart the net trying to find answers and if anything people are saying their HD's POI is high not low like mine. Ammo used was Federal 9mm 147 AE9FP & Winchester White Box 115. I live in The Woodlands north of Houston and member of Bayou rifles range here if anybody has any expert advice or can even meet to help with this issue.