Jan Libourel wrote a wonderful piece in a Guns & Ammo special called "Pocket Pistols" (June 1984) where he compared the .25 ACP and .22 LR in two identical Beretta Model 21A pistols. The .22 LR cme up short of the .25 ACP due to the lighter (and softer) lead bullet. This inhibited the penetration and its effective range, while the .25 ACP's FMJ (generating nearly identical energies) penetrated more deeply due to bullet construction.

One can't deny the immutable laws of physics.

Scott