Yeah--go to a gun store! Most of the people there are absolutely DELIGHTED to help a writer get their firearms details right. They read too!
It saved me from putting a safety on a revolver and kitting it out with a silencer. The clerk explained the design of a revolver makes that impossible. Later I read a thriller where the hero pulled out his "automatic silenced revolver and flipped off the safety." I'm sure that somewhere there is such a thing, but it won't ever be in one of MY books!
Another clerk talked me out of using the wrong kind of gun for a scene in one of my books--it seems that model hadn't yet been invented!
There's a book called "Weaponry For Writers" which is pretty good, but be sure to get the latest edition. The first editions were full of errors.
One weapon savvy writer is
Massad F. Ayoob, who has a number of highly informative, entertaining books that I've found to be very useful in my research. He also outlines the legalities of firearm protection. (If your character drags a body into the house and claims self-defense he will be in for a baaad time with the law.)
Good luck!