Never rely on a .22LR for self defense.
There are inherent problems with the .22LR cartridge, regardless of the quality of manufacture. Let's examine them.
1. The primer is rimfire, not centerfire. A drop of priming compound is dropped into the case. The case is then spun rapidly to get the priming compound to migrate into the rim by centrifugal force. If it doesn't do this evenly, you end up with a no-ignite spot in the rim. If your firing pin hits that spot, it's a dud, and you get killed. This is why Browning designed the .25 ACP, which is basically a center-fire .22. Don't believe me? Look at the dud bucket at the shooting range. Many .22, very few centerfire duds.
2. The bullet is heel-crimped, not seated into the case. This means that the bullet can work loose, either as a manufacturing defect or in handling. If the bullet is loose, it may fail to feed in a semi-auto gun and you have a stoppage, and you get killed.
3. The bullets are lead, not jacketed. Jacketed bullets were designed around the turn of the century, so that self-loading firearms could load them reliably, which they didn't do with lead. If your lead bullet prevents feeding, you have a stoppage, and you get killed.
4. In common with all mouse-cartridges, the little bullet goes too slow for reliable penetration. Insufficient penetration results in superficial wounding, not incapacitation, and you get killed.
.22LR is a sporting cartridge, not a self-defense one.