IANAL but the ammunition you use is unlikely to be relevant in a criminal case. I don't know of a single self defense case where it has been an issue. Any criminal case will hinge entirely on whether you were justified in using deadly force. If you have decided you will use deadly force to defend yourself, have ready the name and number of an attorney who know how to handle self defense cases.
From reading about self defense cases I've gleaned the following:
If you do shoot someone, call the cops, tell them you shot an attacker and give them your address. Put the gun in a safe place in a safe condition. Do not put it in your regular safe unless there is no other option (I have a small handgun safe in the living room and another in the den). When the cops arrive, do not say anything to them beyond:
- I was attacked
- I didn't do anything wrong
- I want to talk to an attorney
- I do not consent to any searches
Do not provide any information except on advice of counsel. A digital voice or video recorder is a good idea but check on the legalities in your area.