(Just like the mythical hand-loads used for self-defense or other handgun modifications are a no-no because those will surely get you in trouble with the law...
An important thing to grasp -- maybe THE important thing to grasp -- is that none of these matters that we discuss in similar conversations "..
.will ...get you in trouble with the law."
Meaning, carrying handloads isn't against the law in any state. Carrying a gun with a modified or removed safety isn't against the law in any state. Carrying a huge Desert Eagle to the mall, or defending yourself with a registered full-auto M-16 with the "Punisher" death's head engraved on it in blaze orange are not against the law. And none of those things appear written in any state's laws regarding factors which support or preempt a self-defense claim in trials arising from violent encounters.
(Edit: With any obvious exceptions for states where a particular gun might be illegal to own, obviously.)
There are two basic factors which
may have effects on your case if and when you shoot someone in self defense:
1) What your decisions to carry might indicate to those who will decide whether or not to prosecute you -- generally based on what they feel they can get a jury to believe about you based on those decisions.
2) (In the case of handloads), some rules regarding presentation of evidence in your own defense.
The first is very fuzzy and nearly impossible to
quantify because it is largely based on impressions given to and accepted by jurors who will decide guilt on facts, without any overt mention of all of the intangible factors that lead them to feel as they did toward the defendant. But, this element plays a vastly important role in any criminal trial. Grandma in her apron, firing through her front door with a single-shot .410 shotgun and wounding someone she thought was breaking in might get a more favorable result from a jury than 250 lb. biker Eddie, covered with tats, who shot someone with his AK-47 clone with "Zombie Killer" painted on it, even if the guy he shot had just kicked in his bedroom door and the shooting is
prima fascie more clearly in line with a black letter law definition of self defense.
The second is a lot easier to qualify because rules of evidence are pretty easily stated and relatively concrete but, in regards to handloads in self-defense cases, appears to actually come up in a vanishingly small number of cases, due to how many details have to stack up just right to make those factors important in a given trial. (Even the famous
Bias case that gets mentioned every time the subject is discussed did not actually hinge on, nor even clearly illustrate, handloads not providing admissible forensic evidence.)
... even if you have a righteous self-defense use of lethal force.
And here again we have the cart before the horse.
We like to jump to the assumption that something
IS a righteous use of lethal force and then we critique the contributing factors based on that assumption. Kind of like we might say, "I know this animal is a fish. The fact that it has horns and hooves, wears a big bell around it's neck, and the farmer milks it twice a day just means the jury made a bad call."
No use of force or deadly force is "righteous" or lawful, or justified, or whatever else we might call it, until
other people decide it is so. These factors are ways we might stack the deck in our favor to get a more favorable outcome, or rather, how we might avoid things that push others to decide our actions were not acceptable under the law.