Years ago I had a 22 long rifle revolver made by a notable American Firearms manufacturer. I took it out of my dresser one day, took it out to the the backyard [which was basically a soybean field] and I started plinking... three out of the six shots did not fire.
I traded it off and got a shotgun to replace it with as my home defense weapon. But I had thought not that long ago that maybe it could have been the firing pin but... it was brand new factory out-of-the-box from a reputable American Firearms Manufacturer.
What happened that day thoroughly convinced many that a rimfire was not a suitable round for self-defense because of that 50% failure rate.
There are other instances of particular makes and models of pistols that I have seen my family use that were completely unreliable as well, yet they retain popularity in the self-defense market. But I will never own them because I have seen with my own two eyeballs these factors of unreliability! Furthermore, I have also personally witnessed the inability of the manufacturer to correct the problems when the pieces were set back to the factory for corrective maintenance.
There is a Firearms testing magazine out there and it cost about 36 bucks a year but they are completely detached from commercial advertisements and they run tests on everything, and they do not sugarcoat any testing whatsoever. I’ve gotten a lot of good information from that magazine over the years.
I no longer need to subscribe to those magazines because as far as my knowledge goes on what and what not to purchase and more importantly, what works for me and what doesn’t work for me, what fits and what doesn’t fit, and what is easily maintainable versus what is a pain in the butt to try to maintain... is set. I know what I need to know.
I only buy CCI and Aguila ammo for my 22s
Probably the AMMO.
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That's why it's important that you never store a revolver with the cylinder bores even the slightest bit wet with gun oil - it will creep into the cartridges and kill the priming compound. The "heeled bullet" design on the .22LR seems to be especially vulnerable to this. .22WMR uses a true copper-jacketed bullet and a crimped case, which makes it less risky.
I had a new factory out-of-the-box from a reputable American Firearms Manufacturer .22LR revolver that had more failures to fire than successful shots, even after cleaning, oiling, etc. I sent it back to them with a clear explanation, and they "repaired" it (much more than a repair, I suspect, it felt and looked like they sent it through their custom shop). I've had probably two failures to fire in 2,000 rounds since then, which amazes me for rimfire ammo. To put it mildly, their repair technician did a very nice job (and saved S&W's reputation for me as a purchaser). It's now my favorite revolver.