Hi
There have been players who have finished the XBOX version- so don't give up
... hopefully they will return and help you!
Some thoughts (Keep in mind I have the PC version, and not quite sure what you have done and what you haven't )...
-Take a close up look of all the bullets yourself and then give them to Greg just to be sure
-the wound is the lower one- squib is in the upper one. Get as close as you can to the lower one (one click) and then try with the microsil. Even the PC version is a bit picky with placement.
-make sure you annoy all the people you can often to make sure no questions are left over
-look at the tape X on the stage (some people forgot this, so I'm writing this just in case
)
-try to find a tool on Gus' tool desk (it's missing).
Also, Greg doesn't really compare the bullets to each other- he does and says he did rather quickly, so you might have just missed him say it. The key is to locate the tool... ie. maybe try and get Gus. Search his prop room and the victim in the morgue thoroughly to make sure you have all the evidence necessary to interrogate him.
hope that is of some help!
K