This whole thing about calibers is a tempest in a teacup. It misses the key factor, which is, was the use of force legally justified? Was it reasonable and necessary? Were you in fear of death or grievous bodily harm to yourself or others? If the answer is yes, whether you use a .22 or an F350 Super Duty has no bearing on guilt. Certainly if it was not justified, a prosecuutor or plaintiff's attorney might use your weapon of choice as an indication of your pre-formed intent, but that won't change the facts as to your justification for use of deadly force. Wearing a T Shirt with "Kill them all and let God sort them out" would probably be more harmful to your case than your choice of caliber.
To illustrate my point, stage 1 of Florida LEO annual qualification begins at 1 yard, draw and fire 3 rounds from the hip, then take a step back and fire 3 rounds point shoulder. That's 6 rounds usually done in 2-3 seconds and your opponent is probably finished but still upright to the end of it. Now the question is going to be, was employment of deadly force justified, not how many rounds were fired. On the other hand, if the suspect is down and out after the first three, the second 3 while he's on the ground and no longer a threat is not objectively reasonable. Caliber has no bearing on whether deadly force was justified to start with.
