A DA will do EVERYthing he can think of to paint you as a psycho gun nut. It's up to you to hire an attorney who is better than the DA. No pat answers can serve all cases specifically.
I would make sure I know what reasons *I* have for carrying a specific caliber, quantity of ammo, carry position, ammo type, etc. Even though you shouldn't have to justify every detailed action you take, you may have to do so.
Most importantly of all, you will have to answer the question of your intent in using or carrying a firearm at all. No matter what, your intent should be nothing more than to stop a threat. Not to kill. All too often, I hear people tell how they have make SURE the bad guy is dead before you stop shooting but if that is your intent, you're going to be taken down for intent to kill, ergo, to murder. No matter what else you do, be sure you understand THAT question and all other issues will follow that intent.