Indeed, I can think of no good way for such a question to be asked. If the goal is truly to attempt to achieve accuracy for a fictional work, the internet is a good place to ask since most answers will also be fictional!
As a relatively knowledgable gun guy, I'll admit to finding firearms related errors in a story mildly off-putting. I try to get past them though and remember that I am, after all, reading fiction.
In most cases, unless the writer has solid first hand knowledge, he is best off to keep things as simple as possible and don't try to get too cute. I would never try to write a story in which flying a plane figured heavily because I have no firsthand knowledge. If I had to put a plane in there for some reason, I would try to avoid saying too much so as to avoid saying something too stupid!
Terminal ballistics are a complex subject and the use of complex subject material as a major prop can afford an opportunity to be clever or foolish. I feel, if the storyline must be supported by such a reference, the reference should truly be accurate. If the storyline can stand without the reference, perhaps it should do so. GD