I heard someone the other day saying that you can do that?Is this true?Is there any danger in that practice cause near as I can tell the cartridges are close to the same power range but it does not sound like a good idea to me.

The .32 ACP is a rimless cartridge which headpaces on the case mouth. The S&W cartridge is rimmed and headspaces on the rim. Unless the chamber is cut for the ACP, it will simply fall to the bottom of the chamber when put in the cylinder.

The .32ACP is not rimless.  It's a semi-rimmed case, and will headspace on the semi-rim in a revolver.  It won't fall through a chamber cut for the .32 S&W long.

It used to be common knowledge that the .32 ACP could be shot out of a .32 Long revolver and was printed in most manuals and handbooks of old.  Liability concerns have erased the idea from print for some years.

Of course, many things that were common knowledge "back in the day" aren't in print because they were bad ideas as well.

As a general rule, it's never a good idea to shoot ammo that wasn't designed for it in any gun.

Another cartridge that is semi rimmed is the .38 Super.  You can fire it out of a .38 Special/.357 Magnum.  Again not recommanded.

CD

Quoted: Another cartridge that is semi rimmed is the .38 Super.  You can fire it out of a .38 Special/.357 Magnum.  Again not recommanded. CD

Good Luck with that!!!

.38 Super operates in the 33,000 psi range or about double the .38 Special at 16,500 psi.

Likewise, the .38 Special case is .379" diameter whereas the .38 Super is .384"…

Quoted: Quoted: Another cartridge that is semi rimmed is the .38 Super.  You can fire it out of a .38 Special/.357 Magnum.  Again not recommanded. CD Good Luck with that!!! .38 Super operates in the 33,000 psi range or about double the .38 Special at 16,500 psi. Likewise, the .38 Special case is .379" diameter whereas the .38 Super is .384"…

Depending upon the chamber tolerances, the .38 Super will fit nicely in a .357 Magnum.  I've noticed that it will typically fit in a S&W, but not Colts.  I haven't tried it in other brands.  Mind you, I haven't actually dropped the hammer on a .38 Super in a .357 Mag.  I've just test fitted them out of curiousity.

It has been suggested that the semi-rims on the early ACP cartridges were included out of the possibility of dual use: pistols and revolvers.  I know that some small European revolvers have actually been chambered in .25 ACP.  In addition, the Webley-Fosbery automatic revolver was offered in .38 ACP, besides the standard .455 Webley.

Quoted: Quoted: Another cartridge that is semi rimmed is the .38 Super.  You can fire it out of a .38 Special/.357 Magnum.  Again not recommanded. CD Good Luck with that!!! .38 Super operates in the 33,000 psi range or about double the .38 Special at 16,500 psi. Likewise, the .38 Special case is .379" diameter whereas the .38 Super is .384"…

.357 is in the 35,000 psi range, though.

NOTE: I am definitely not recommending shooting off-list calibers through firearms not designed for them.