Ok this is my second post after my introduction. First let me say this is my major enjoyment in my life, and I know next to nothing compared to others when it comes to this subject.
The problem - Writers will always always fuck up things they don't know. No matter what they do or hard they research topics its gonna happen. The Dresden Files have a few slip ups, and for instance as engrained as some characters are to weapons a few statments make gun owners mildly cringe. Now that said its part of a culture thing, and I don't expect Mr. Butcher or anyone else who isn't balls deep in firearms to catch onto everything. It would be like me trying to write a story about web design....
The solution - First most of you that write will either know your subject, create something new, or research. Firearms are the damn hardest thing to research and understand. There is science out that will give you most of the answers, and people who will know a great deal. Two major problems seem to happen. Most people who believe they know firearms either back up there evidence with opinions, emotional responses, and out dated information. There are many forums dedicated to firearms, guns, and military but few hold a great deal of knowledge. Although you will get the right answer some where in a reply to a question it might be filled in.
I will list a forum for you guys that will have people that are highly knowledgeable, and a few others for you to look at(you can view but they close off industry people) So you can get answers from cops, to military, and about every weapon. Just so you know post a introduction in "The crusader Hall" first before you ask your question. When you post in the forum state why your need the information (IE I am writing a book and would like to know....). We have a guy on the forum that helps movies get more accurate production, mil, LE, firearms instructors,etc etc.
www.lightfighter.net - Join and ask questions
www.10-8forums.com - Read only, but full of great info.
This is why its becoming more important for some authors. Most people who shot, soldiers(who probably read more books to pass the time then anything else) do pay attention. We as a culture nearly gag when we here someone flip the safety on a glock. Pull out a 45 ACP and blow someone away, actually to pieces away, not just injured/dead. Contrary to popular belief case studies, science, and ballistics testing show that the difference between a 9mm 40 and 45 are almost negliable. Also a pistol is a pistol, not a rifle. I have read stuff from the guns can't fire underwater (the expert in the book stated fictionally of course), to people not know that shooting through a windshild actually makes the bullet turn direction 5-10 degrees maybe more. FYI contrary to Mythbusters most handguns will repeatedly shoot underwater. However the 1911 has a odd thing where the shell comes out of the chamber and then goes right back in backwards. Seen that myself on a two 1911s, and had a magainze author report the same thing. Might not seem like anything worth knowing, but maybe your Hero jumped in the water etc with a pistol etc. You can ask if its possible.
Ask these guys if you write a story and you want a bullet to do something, or know about how silencers work, sound, or even act. Granted most people here are probably more scifi oriented, but if your gonna do the gun thing, and you do it write you will get a large respect from people who shoot, cops, military etc. We tell people about books more then I think any other run of the mill community seems to, short of book clubs. Long shitty hours board to tears, or hell stuck in a bunker gets you reading anything.
Anyways sorry for the rant, but if you need help on subjects like that start there, and although I started at thehighroad.org peoples biest and knowledge about which is best etc seems to be more about how they feel, then reality. Hell you might learn something interesting on the side.