I've never seen a "compact" .45, but then it's been some while since I've been in a gun store. The smallest .45 I would handle would be a Glock. It's nearly indestructible, light weight, and has a good grip. (I have long fingers.)
Contrary to rumor, "plastic guns" show up quite clearly on airport x-rays. They have more metal in them than the average machete.
I STRONGLY suggest you find a local gun store, go in, and ask. You will find the staff pathetically eager to help you get your firearms details correct. Just not when they're busy, like on a Saturday.
By doing that, I was able to avoid a number of mistakes in several of my books. (Wrong caliber, safeties on the wrong models, the difference between a pistol and a "gun" [guns are usually cannons, I found out!], gun myths, etc.)
Writers who get gun details wrong get struck off my reading list.
Trevanian--wrote thriller spy stuff in the 70s. I stopped reading him in chapter one of his most famous bestseller because a character carried an automatic revolver kitted out with a silencer. (There's only one automatic revolver I know of, the
Webley-Fosbury model, which killed Miles Thursby in The Maltese Falcon.) Revolvers cannot be kitted out with silencers at the end of the barrel because all the noise is generated elsewhere on the frame. It's a Physics Thing.
Sara Paretsky's popular V.I. Warshawski's PI walked into a gun store and bought a specific model, a .38 8-shot revolver. The named model carries only 6 shots, and
that state had a 15-day waiting period between purchase and delivery. I checked with a gun store owner on whether he would skip the wait for a pretty girl with a black eye. He said NO way, it would cost him his store.
George C. Chesbro, author of the Mongo series and former VP of the MWA, had a safety on a revolver (they don't have them) and loaded it with a "butt clip." Revolvers are loaded through the revolving cylinder (hence the name). Semi-autos are loaded through the grip, and it's called a "magazine" not a clip.
http://en.wikipedia.org/wiki/Revolver
http://en.wikipedia.org/wiki/Semi-automatic_pistol
The 33 Worst Mistakes Writers Make About Firearms.
Program takes Mystery Out Of Firearms For Writers.
Firearms Terminology for writers who don't shoot and characters who do.
Please, for the sake of your readers who DO know about guns, get your details right. More women are into sport shooting than you'd expect!