I can't speak for others but I always opt for heavier, slower, bullets when shooting at targets that must react to score. For falling steel matches, I have had the best luck with 147gr 9mm (if using 9x19mm) loaded to around 950-975. When bowling pin was a thing, I shot a .45ACP (set up to run hot 200-230gr loads) in the morning and a .44 Mag loaded with 300gr or 320gr in the afternoon.
If you are looking at moving a solid target (and not incapacitating a soft one) then momentum, not energy, is where you want to look.
Sadly, optimizing for knocking over steel plates will compromise your flat trajectory. A 115gr +P will be your best bet for "standard" ammo in that department but, if you are willing to go a bit more exotic, 88 and 90 gr .355 projectiles can be had. Never used them in an AR 9mm but we did play with them in MP5s a bit.
If you are looking at moving a solid target (and not incapacitating a soft one) then momentum, not energy, is where you want to look.
Sadly, optimizing for knocking over steel plates will compromise your flat trajectory. A 115gr +P will be your best bet for "standard" ammo in that department but, if you are willing to go a bit more exotic, 88 and 90 gr .355 projectiles can be had. Never used them in an AR 9mm but we did play with them in MP5s a bit.