Practicing help.

Question for the form. I’m currently practicing with my 16” 5.56 ar on a weekly basis. I am fortunate enough to have a 300 yard range right behind my house. I have been for the past few months been practicing shooting between 100-300 yards just kinda shooting few rounds at a 100 standing unsupported then shoot few at 300 standing unsupported. And a lot of practicing is for hunting/self defense. After all that my question is my time at a 100 is roughly 1.5-2.5 seconds between shots that is as fast as i can accurately pull the trigger without a just missing all over the place, and I just can’t seem to shoot any faster than that and put rounds on targets in an acceptable group and I just wanting to know does anyone have any advice to slim down that time?