Iām done with stopping power debates after reading about this murder case five years or so ago where a guy living in a trailer was attacked. He killed the thugs using a .22LR pistol.
In contrast, a stormtrooper with the most advanced weapon but couldnāt hit anything.
I have always believed (and preached) that shot placement is more important than caliber.
The smallest round can do a great deal of damage when placed with precision into a vulnerable spot. But precision aiming takes time; time which you may not have. A large caliber round can do great damage to a larger area, thus the placement need not be quite so precise to accomplish your goal.
The reality is that an āideal defensive caliberā is a compromise amongst a number of variables.
- The weapon must be able to be comfortably and securely carried in such a manner as to allow it to be accessed, placed in battery, and presented to the threat very quickly.
- The weapon itself, as well as the caliber and load, must be one that the user can handle and fire rapidly with one hand from a variety of positions while maintaining reasonable shot placement (center mass).
- The weapon must be capable of a high degree of precision when the user has the time to effect a proper stance, grip, and sight picture.
Just a few of the factors which inform the compromises to be considered. It has taken me tikme, effort, and treasure to determine MY ideal carry weapon. Iām getting close! 
About 15 years ago, a guy I know and his wife were awakened in the middle of the night by the sound of pots, pans, dishes, etc. clanging in their kitchen. Investigation revealed it was a raccoon rummaging their house looking for food. Try as best they could, they were unable to force it out an open door. Instead it moved further into the house. The guy grabbed his 22 loaded with ratshot, put an empty 2 liter soda bottle over the barrel as shown in your photo, and shot the raccoon off the fireplace mantle! He said he was very surprised at how well the bottle suppressed the gunfire. He said it did such a good job that neither of his children woke up. Of course they must have been pretty sound sleepers since the raccoon ruckus didnāt seem to wake them either.
BTW, the fireplace was on an exterior wall, so no risk of over-penetration nor endangerment of his children.
I ran across this study once. What jumps out at me is that all the major defensive handgun calibers have pretty similar numbers in terms of one shot stops, and number of shots until incapacitated.
āThe idea of stopping power is a mythā eh? go shoot an elephant with a .22 short and tell me stopping power isnāt a factor lol. We calculate muzzle energy and set āethical caliberā standards in hunting for a reason, because yes, stopping power is in fact a thing. will .22 NEVER kill the elephant? no, eventually you will get lucky and feed one through its eye down the optic nerve channel and into the brain, but the likelihood of you pulling that off are pretty slim. The likelihood of you pulling it off while being charged are pretty much zero.
Is there an argument to be made between 9 and 45 for stopping power? Anecdotally, sure, but the margin is a lot smaller than one would think. Now, compare calibers that are little further apart in purpose, and you will start finding all kinds of stopping power issues. Compare .222 vs 7mm magnum. Compare .22-250 to .416 rigby. see what im getting at?
I also know for 100% fact that soda bottles work just fine with subsonic .22 LR lol
counter point to this argument is the woman in Petersburg a few years back that was shot in the back of the head at point blank range with a .32ACP and the round didnāt even make it through her hair. Anomalies are anomalies for a reason, they are not the standard and people shouldnāt think a weapon with a 20% effectiveness is comparable to one with 80% effectiveness just because we can cherry pick a handful of instances out of thousands of cases.
Stopping power has nothing to do with common senseā¦
If somebody hunts elephants with .22 it is not a lack of stopping power knowledgeā¦ it is lack of brainās functionality.
Because we are here for defense discussion, using different caliber doesnāt matter if you know how to shoot, how many times press the trigger and where to aim.
Regarding āsoda bottle silencerāā¦ yes it definitely works for .22š
The shot sound with bottle is about 87 dB, when without the bottle is 87 dB 
Actually all depends on the environment you are shooting at and the round load.
Sometimes it may work reducing the sound a littleā¦ but itās not the same as a real silencer.
Quite true, such as being charged by an elephant here in America.
The question of āStopping Powerā is essentially one of picking a tool suitable to the task. Ideally, suited to a range of tasks one may reasonably encounter. Simply because elephants exist somewhere in the world and have been known to occasionally charge a human is not a rationale for carrying a .50BMG to Walmart.
Given a choice, a .22 of any loading wouldnāt be my preferred defensive carry weapon. That being said, a well-handled .22 may be more effective than a poorly handled .357 or .45. There are far too many variables to be considered regarding the attacker, the defender, and the surroundings (to name only the obvious) to make a blanket statement defining the ābestā caliber(s). One size almost never fits all.
Valid point.
Gonna throw this in because I carry on a daily basis, the ammo in my opinion is your key to stopping power, I donāt believe that you want the round to pass through as a 9 mm or larger may do, but if you have a round like ARX rounds which acts like a shotgun shell and stays in the body and does a lot of damage where a standard 9mm hollow point even after it expands could still pass through the body and possibly enger someone behind them, just saying.
I knowā¦ itās in Polishā¦ but this is an āoil filterā bought on Aliexpressā¦ 
Accidentally this filter fits on threaded barrel on his .22LR.
It may be an old wives tale.but the best proof of handgun stopping power came from the US forces in the Philippines using .38 revolvers and still getting bayoneted.Its why they switched to the 1911.It supposedly solved that problem.
Was on the range this morning with my .45acp.
Three rounds, itās not a myth! When I turned around nobody was moving. Thatās stopping power!
Iād read that same thing. Specifically, I believe they were using the .38 S&W, and the dismal results led to the development of the .38 Special.
Edit to add, I just checked, and they were using .38 Long Colt, not .38 S&W. Either way, the obsolete .38 cartridges were both too weak, which is how we got .38 special and then magnums.
Magnum P.I. has a lot to answer for with that one lol.
Where I live there are a lot of fat people. The elephants at the zoo are confused sometimes as to who should be throwing the peanuts.