It looks like you are comparing a 5 inch 9mm with a 2 inch stubby 38 special.

BBTI - Ballistics by the Inch :: 9mm Luger Results

BBTI - Ballistics by the Inch :: .38 Special Results

By the way, when I was young the police all carried 6 inch barrels, except the detectives. In 158 grain the penetration is very good. Longer heavier bullets penetrate better.

No one would have dreamed of carrying a 9 mm until hollow point bullets and high capacity magazines became available.

In the 9mm the round nose jacketed was the only thing available. Good for punching little holes that stretched out and closed back up.

In the 38 special the reliability and flat semi wadcutters were nice. Lead bullets go down the barrel a little faster than jacketed, in any particular caliber. They also reload nice.

There was no such thing as +P 38 specials back in the 1950’s. All S&W revolvers were made of steel, and all the old loads would be called +P today, if memory serves.

In other words, back then, everyone sooner or later compared them. But the jacketed round nose 9mm geneva conventions military bullet was not a good man stopper.

I would be willing to bet that most off duty police still carry stubby revolvers. I might be wrong?

You might notice in reloading books the powder in the shells is about the same, or slightly more in +P 38 special.

The powder does the work.

The Kabooms and interesting jams just do not happen in revolvers. But the semi-autos are getting better. Some semi autos still have a hammer that you can cock for better shooting. Back in the day there was no good triggers on single action auto’s. Even today the semi autos have hammers that are awkward to cock.

I shoot better with stubbies than little semi-autos. As pocket guns they have no equal. Show me a semi-auto you can shoot from inside a jacket pocket in an emergency.