ballistics evdence

Question
QUESTION: Is it possible to determine if when two shots are fired which projectile was fired first?

ANSWER: It depends, too much info unknown, you can tell where the casing fly and land, you can spray patteren of gun reside, you can find other factors that may give that answer, but just by looking at the bullet, probably not unless the something want change between the first shot and second shot.

---------- FOLLOW-UP ----------

QUESTION: Thank you for your response.  On pondering this further I was wondering if a deeper forensic examination of the bullets and/or casings may assist as I am hypothesizing that changes in the barrel temp and rifling due to the first shot may allow you to identify which shot was most likely the first.  Can you provide any insight into my theory?

Answer
It sounds reasonable, but not aware of that advanced technology. Each round fired is never the same since you have burnt powder, lead or copper shaving and other debris left from previous rounds. If you fired 5 rounds int he same conditions you may be able to tell how each one fired changed, but he changes would be so minute that it would be hard to prove, but sure it could be done, but making all conditions exact would be near impossible.