You can get a rough idea about 22 performance from here:
http://www.ballisticsbytheinch.com/22.html
using the colums "Remington 36 gr. Golden Bullet HP," "CCI 40 gr. CPRN Mini-Mag," or "Winchester 40 gr. Super X RN" would probably come closest to the ammunition you have available. Going down the left hand side, you can see the effects of barrel length on performance in feet per second. If you click on the headings of each bullet, a graph will come up for all barrel lengths for that ammunition.
Below, you will see actual testing done on a number of individual guns. A revolver of the barrel length you want to study would probably be the best bet here for the information you seek.
Note that the gun itself plays a role in performance, for which this doesn't provide information. No IOF revolver is tested. Excessive cylinder gap and loose chamber or barrel tolerances will make a difference here. Since IOF revolvers may exhibit a lot of gun to gun variability, the only choice for exact data is to chronograph the individual gun in question.
As you see, the more precision you want in the data you request, the more difficult it is to obtain. I suggest you start with the upper table and simply compare barrel length performance for a "rough and dirty" indication of velocity.
Next, the question will come up, how will the bullet perform on a target?
This archived site has such information for certain ammunition fired from a 2 3/4" barreled Taurus revolver:
https://web.archive.org/web/20111223095 ... el22lr.htm
I would suggest that you use the "Federal Lightning 40gr" and the "Winchester Wildcat 40gr" information to answer your question. Even in bullets that look the same to the naked eye, penetration can differ due to subtle changes in the shape of the bullet. Going by this information, you can make adjustments to the velocity to account for barrel length. Hard and precise figures aren't available because you still aren't dealing with the same gun or the same ammunition, but you can get an idea of the variation you might expect between different length barrels.
The important thing to consider is that penetration does not equal the minimum of 12" recommended for reliable stopping. This figure is verified by USA FBI testing in real world situations, and takes into account cases where different thicknesses of clothing or hitting a bone might take place.
As you see, while a 22 LR cartridge can certainly be deadly, its utility for self defence is less, sometimes considerably less, wtih a shorter barrel. For a reliable stopper, you are going to have to consider moving up into the 32 calibers, which are marginal also, but much less so than 22 LR.