It is a .22 with around 9mm energy in better loadings.
Penetration of thin barriers should be excellent for the energy.
However terminal performance is severely lacking. The wound channel is far too small. Even with the ammunition designed to make it partialy effective it has experienced many problems failing to provide adequate stopping power. Civilians are unable to even get that ammunition.
It is designed to provide a better wound channel by bending into a sort of L shape after impact and flipping in the target to make up for its small diameter, which it only does some of the time on realistic targets of bone and tissue.
If you follow the round from its design to its production the entire purpose of the round was to provide penetration of body armor, and then manage to have stopping power of a larger diameter round while remaining in the realm of pistol energy.
Removing any of the elements necessary to accomplish this from the round, which is what all of the civilian legal rounds do, destroys its already marginal effectiveness.
The civilian rounds do not flip, they do not come out in bursts or on full auto to make up for poor performance of each individual round, and the only thing they share in common with the round responsible for this caliber even existing is the dimensions. They are totaly different rounds, not even comparable.
The civilian version is basicly a very speedy varmint round. The absolute only reasons to consider it for anything else would be low recoil and high capacity. You could put half a dozen shots where you want them in the blink of an eye, but its going to take 2-3 shots to accomplish what 1 of other popular defensive calibers does. If however you have any capacity limitations like some states and localities do, then it becomes even worse of a choice.
Furthermore none of the firearms chambered in this round make use of the small dimensions of the round in creating a pocket size firearm. The selections are of full sized guns with poor ballistic performance.
In CA with a capacity limitation of 10 rounds, poor terminal performance, traditional rounds designed to increase the diameter of the wound channel by mushrooming rather than flipping (with flipping being the only reason it even becomes a marginal round) and a large size gun, it is basicly a combination of every single feature you do not want in a self defense firearm: Low capacity, low performance, and large gun.
For varmints it should work great, it is after all a very fast .22 that will mushroom into an explosion once it hits a little animal. A bit pricey for soley a varmint gun though. The trajectory will also make it a hazard to people for a longer range than many varmint shots.
