The '92 isn't a bad sidearm at all, they just happen to be a bit larger than other 9 mm alternatives. The 9mm caliber is also what was a bit humorous when in the movie Murtaugh commented that Riggs was packing some "serious power," when Dirty Harry was using a 44 magnum. An average 9mm round after fired typically travels around 1140 feet per second and has ~360 foot pounds of energy. A 44 magnum round travels around 1320 feet per second and has 900 foot pounds of energy. The magnum is substantially more powerful. The only thing I could think of is they might have been alluding to the 15+1 capacity of rounds, which was a huge step up from police standard issue .357 magnum revolvers of the time in Los Angeles, which were six shooters. Even with a speed loader the Baretta had a big edge in a firefight in terms of volume of lead they could put in the air. The .357 would hit way harder, though.
