Which one? They are several different models.
Beretta made a LOT of different 9mm pistols. However, if you are asking about the M9 pistol used by the US Army, it is about 8.5 inches long.
There is no such thing as a "9mm Beretta" cartridge. Beretta firearms were manufactured in 9x19mm (also known as 9mm Parabellum or 9mm Luger), 9x17 (also known as the .380 ACP), and some models are made in 9x21 IMI for countries which prohibit civilians from owning firearms chambered in military calibres. The cartridge appropriate for your Beretta 9mm should be marked on the frame and slide.
Contact Beretta.
9mm Parabellum
first, problem won't happen. the 9mm case might fall down the beretta barrel. the 40 cal. is a larger case then the 9mm. so, you can't fire a 9mm in a 40 cal nor a 40 cal in a 9mm barrel...........your safe....... Well, I did it! The 9mm was picked up by the receiver and fed into the barrel. It fired but the extractor could not extract the swollen cartridge. I have reason to believe the bullet bounced down the barrel and tumbled on its way to the target. BUT...what COULD have happened?!?! The worst that would likely happen is a major case rupture which could result in you missing a hand and your eyes. Theres a very good reason they stamp the caliber on the side of firearms.
9mm Parabellum- often called 9mm Luger.
380 ACP or 9mm short or 9mm corto
Check the Beretta website.
From 1950 onward, Beretta produced several notable models in 9mm, including the Beretta 92, which was introduced in 1975 and became widely recognized. Prior to that, the Beretta Model 951, a single-action semi-automatic pistol, was available since the early 1950s. Additionally, the Beretta Model 1934, while primarily chambered in .380 ACP, was also adapted for 9mm in certain configurations. These models highlight Beretta's commitment to producing reliable sidearms in the 9mm caliber.
First it is Beretta, second, it is a magazine, not a clip. There are several different 9mm models made by Beretta- it will use the magazine made for that model.
You will have to call Beretta
Loaded or unloaded?