Not sure if this will shed any light on your questions or not, but over the years I have owned a couple 2" Small Frame .22 LR Revolvers. Back about 12 years ago I owned a really nice little Smith & Wesson Model 63 Double Action Revolver. While in possession of this little Revolver I did chronograph a few different brands and types of .22 LR through it.
40gr. Federal #711 Champion = 923 FPS / 76 FPE
40gr. Federal #711 Classic = 907 FPS - 73 FPE
40gr. Federal #711 Gold Medal Target = 868 FPS - 67 FPE
40gr. Federal #805 Rifle Match = 905 FPS - 73 FPE
40gr. Winchester T-22 = 889 FPS - 70 FPE
40gr. C.C.I. Standard Velocity = 877 FPS - 68 FPE
40gr. P.M.C. Target 22 - 873 FPS - 68 FPE
40gr. Hanson Target - 872 FPS - 68 FPE
40gr. Eley "Match" Black Box = 897 FPS - 71 FPE
32gr. C.C.I. Stinger H.P. = 1121 FPS - 89 FPE
36gr. Federal Hi-Power H.P. = 939 FPS - 71 FPE
36gr. Remington Hi-Velocity H.P. = 883 FPS - 62 FPE
40gr. Federal Hi-Power = 924 FPS - 76 FPE
40gr. Winchester Hi-Velocity (Super-X) = 912 FPS - 74 FPE
40gr. Remington Hi-Velocity (Golden) = 891 FPS - 74 FPE
Now remember this test was done 12 years ago or so, and some of this ammo is either not available today, or has changed over the years.
More recently a couple weeks ago I did a similar velocity comparison with a friends 2" Taurus Model 94 Double Action Revolver. The purpose of this test was to determine which ammo (of what I had on hand) would provide the most Muzzle Energy for self defense.
40gr. CCI Blazer = 929 FPS - 77 FPE
40gr. Wolf Match Target = 804 FPS - 57 FPE
40gr. CCI Velocitors Hollow Point = 993 FPS - 88 FPE
60gr. Aquila Super Subsonic Snipers = 689 FPS - 63 FPE
31gr. Federal SpitFire Hyper Velocity Hollow Point = 1042 FPS - 75 FPE
36gr. Remington BULK Hollow Point = 856 FPS - 59 FPE
38gr. Remington Sub Sonic Hollow Point = 792 FPS - 53 FPE
36gr. Winchester BULK X-Pert Hollow Point = 972 FPS - 76 FPE
Granted this does nothing to answer your questions, and no I have never owned nor fired a .25 ACP. However it should give you an idea as to the ballistic performance of the .22 LR when fired from a concealable 2" Barrled Handgun.
I had envisioned that the 60gr. Aquila SSS would be the ammo of choice for self defense in the little 2" Taurus. Well in shooting this ammo I quickly learned that the Rifling Twist of most .22's is not made for this bullet as most key hole through the target. However even key holing, at 7 yards shooting the little 2" Taurus double action, rapid fire I could manage to print 9 shot groups of about 3" or slightly less. This accuracy level would suffice for a self defense situation, and the tumbling bullet may or may not create a devistating wound. However after shooting this limited amount of ammo I think if I were going to rely on a .22 LR as a Back Up Weapon / Self Defense Weapon I would more than likely load it with CCI Velocitors.
Larry