Wow, this is still going on? Talk about angels dancing on the heads of pins!
What are the odds that proving your guilt or innocence would come down to your ability to get your reloading records admitted at court? (These are not automatically inadmissible, by the way: it would be left to the judge's discretion.) And, a person could testify as to what he loads were, have his own expert load identical rounds and perform the testing and give testimony as to how they worked - again, like all evidence, admission is subject to the judge's discretion.
As I've said before, I feel that there are much bigger things to worry about. If a person were to dwell on all of the horrific potential unjust outcomes that could arise from a righteous defensive shooting (or from someone unauthorized getting a hold of his guns), he would do well to sell his guns. All we can do is make responsible decisions based on likely outcomes.
I carry handloads. Not always, but I do. For the most part a good shoot is a good shoot (and an unintended shoot is always a bad shoot), and my rounds are designed to do exactly what I intend from my gun. No factory worker assembles ammo with the care that I do my handloads. I practice with what I carry, so I know how it works and I'm good with it.
But what advice would I give a client? What advice
did I give my little brother when he started carrying? Bro. Mas' advice! I said, "It's unlikely to ever be an issue, but why risk it? Why add a variable to your hypothetical shooting that could in any way come back and bite you?"
I don't give advice for free, though - so this post is not advice, it's me talking about me and what I do.
You see, you'll be held accountable for your actions. The world has sharp edges, and deadly weapons are certainly tricky ground. Everything is a cost/benefit analysis. You're grown-ups - do whatever you decide makes the most sense for you.
I know a way that you can guarantee that your handloads don't come back to hurt you in court: don't carry them.
I also know a way that you can guarantee that you don't ever have to go to court on gun related issues: sell all your guns through a licensed dealer, and have him dispose of whatever ammo you have around the house.
Carrying handloads certainly adds another variable that could possibly come back at you. But I worry a whole lot more about not missing what I shoot at (there's something that comes up all the time in shootings) and about securing my guns so that no one takes one and hurts someone else or himself with it.
You folks be careful!