[earplug]

The question was concealed carry. The answer should be qualified as to weather, body size, style of clothing and body build and activity.
A 1911 under a T-shirt may be covered. It won't be concealed. A service pistol may be a fine choice to fire. It may not be a good choice for a CCW.
Pistol ammunition has not progressed much in the last 100 years. Smokeless powder and the human body have not changed much. The 38spl, 9mm, .357 and .45 all stand the test of time. Fancy expanding bullets for pistols are as shiny fishing lures for fish. Many new pistols rounds are the result of government rules.
We need to consider possible multiple shots, inclosed confined space (muzzle blast) and muzzle flash when firing in darkness.
I'm to lazy to pick up my brass and I don't get paid enough to carry a service size pistol. A M38 S+W is fine for me.

[Servant of the Nine]

The question was concealed carry. The answer should be qualified as to weather, body size, style of clothing and body build and activity.
A 1911 under a T-shirt may be covered. It won't be concealed. A service pistol may be a fine choice to fire. It may not be a good choice for a CCW.

I have conceal carried a 45 for years. First a Detonics Combatmaster in the '70s. Later a Para Ordnance P-10. Now usually a Para Ordnance Double Action Ultra Cary. They are all smaller than a Walther PPK or a S&W J frame 5 shot with 2 " barrel and being flat, they are easier to conceal than the Smith.

So9