Just a bit of large bore handgun humor, if you will, brought on by your script descriptions of handguns. In short, I don't think you need to describe handguns like that. You have an action movie, so a simple
automatic pistol would work, but since you did take the time to say 9mm, and
S&W Sigma and all, it's important to you and you think it's important to the story. I don't think so. It's distracting. From a distance no one will be able tell what kind of handgun it is, unless it's a revolver, aka Dirty Harry.
I can't imagine Inspector Callahan saying "I know what you're thinkin', did he fire fifteen shots, or only fourteen. Well to tell you the truth in all this excitment I've kind of lost track myself. But bein' this is Smith and Wesson Sigma nine-milimeter semi-automatic handgun, not the most powerful handgun in the world, and a whole clip of of these would whittle away your neck so your head would fall clean off, you got to ask yourself one question..."
What you have is a gimmic title of Smith and Wesson (Tango and Cash) and to spice it up you describe a Smith and Wesson hand gun. Dirty Harry didn't describe his .44 mag as an S&W, but he had one and when it went off it sounded like a cannon. So much so that his
lucky punk line went down as one of the best lines in movie history.
When you make descriptions like this, it tells me I'll encounter more detailed descriptions that seem like they mean something but they don't, like
a can of beef ravioli. Unless it's tres important (more important than just eating it), don't get specific because (for me) it becomes a disctraction (I spend time thinking about something that doesn't matter).
To summarize, nines go POP, .45's go BOOM. Do you want a POP action movie, or a BOOM action movie?