Had a customer that ordered the finnish suomi md 31 9mm with 2 stick mags and the 71 round drum,he also ordered the Polish PPSC 43 semi auto pistol in 7.62x25 mm. The suomi is very heavy but was decently accurate and fed flawlessly-great fun to shoot. The polish PPSC 43 pistol went full auto on the first clip blast to shoot ,but alas it was imediatly returned the the supplier. I agrre with the others 9mm carbine is alot of fun to shoot and could be useful for self defense. If I was buying one it would most likely be the KEL-TEC light weight folds up and use common mags -glock,beretta,etc. Or one in an Ar platform such as the bushmaster carbon fiber or the JR rifle, reasonably priced and lightweight,a familiar platform.