Just the forensics of it - especially low-power loads. Typical load should travel at "x" speed, cause "x" type of injury at "x" distance, leave "x" amount of powder at "x" distance...
Low power loads - just like the example in the article linked above - you cap a shitbag at 7 yards, but the low-power load leaves residue like factory ammo at 20 yards... You say you shot the shitbag at 7 yards. His two buddies say you were arguing at 20 yards, and they weren't approaching you. What does the data say? Can the defense team recreate the situation, with the remaining ammo in your firearm? Nope, you emptied the mag. Now, you go home to grab more ammo - and everything has been confiscated already... You tell them that the load you shot the shitbag with was from "xxx" batch.
Prosecution says, "He can create any deadly combination he wants, obviously..."
Bottom line, if they push it, is that you're fucked.
Stick to factory ammo in carry guns and duty work. One less thing for them to F you in the A with. Besides, you won't look "shady" to the jury - the prosecution is going to try to make you look shady as fuk anyway, you can count on that...