How about a .40 cal. J frame?

[elm_creek_smith]

Colt used to make a 5-shot revolver called the House Pistol in .41 RF and another called the Cloverleaf that held 4 shots of .41 RF. That's about as close as you'll get in a little gun.

ECS

 

[Moonman]

If you want a BIGGER HOLE, look to a slug in a 12 Gage, it points better, leaves a bigger hole and is generally more impressive to the person or persons it is pointed at.

"J-Frames" are kinda of secondary deal if you're interested in protection and Big Hole Punchers too.

 

[Erich]

Kinda hard to pocket-carry a 12-bore, tho.

Cartridges with .357" diameter bullets are literally what the J-frame was designed around - and it was the smallest revolver of the time to chamber the .38 Special. As discussed on the first page, the J-frame just won't accommodate a .40. Other guns will - some (say the PM40 from Kahr) are a bit smaller than a J-frame: if you want a .40, buy one and have fun. But, in the same way that you can't buy special shoes to make you shorter, you can't stick a 10mm pole in a 9mm hole.