I've had a PMR-30 for about two years, now. I was on a waiting list for a long time, and paid about $440 for mine.
I don't shoot as much as I used to, so have only put maybe 700-800 rounds through it.
- I've had ONE .22 WMR round that didn't fire so far, so reliability of the .22 magnum ammo, at least for me, isn't that much different than some of the cheaper center-fire ammo over the years, and it's proven to be quite a bit more reliable than most of the .22lr I've used.
- The .22 magnum round is MORE costly, but higher costs don't keep me from firing 9mm or .45 when all I'm doing is putting holes in paper, so I don't really understand the complaints about .22 magnum being more costly. (At the range, its about fun and improving skills, not cost effectiveness.)
The PMR-30 itself seems to be pretty reliable. And VERY accurate. And light. And once I learned to load the magazines -- I finally read and followed the manual instructions -- I've had no feed problems. It came from the factory with a surprisingly crisp and light trigger. My PMR-30 would NEVER by my carry weapon of choice, but I'd probably grab it before a different .22, and the Hornady Critical Defense competes very favorably with some .380 ammo in terms of gel performance.
There are some .22 magnum rounds NOT recommended by Kel-Tec. I've been using Winchester and Hornady Critical Defense (which has been designed for shorter barrels) without problems. Except for the Winchester, which I got at a good price, I try to avoid .22 magnum ammo intended for longer barrels; the fireball is big enough when shooting the stuff designed for short barrels.
I actually bought some Armscor 40 gr. 22 magnum ammo before I bought the gun; I then read the notice in the gun case and found that Kel-Tec said don't use Armscor, Fiocchi, or any non-US-made ammo. I ran three boxes of the Armscor through it without problems. (I figured, since I had bought it, I might as well try it. I won't buy any more -- because it's hasn't been that much cheaper!)
My wife wanted to shoot some, but had a hard time with recoil and with racking the slide with most guns. She can rack the slide on the PMR-30, and while it's loud, the absence of recoil is a plus for her. She wanted a gun SHE could use if ever I'm away for a while and she felt the need to have a gun she could use in the house, and she's still learning to shoot it.
I can say, however, that If not hitting what she's aiming at is a problem, the fireball and loud report might be enough to scare away an interloper. (We do keep hearing protection near the guns stored in small safes in the house.)
As someone else noted, you can get a Ruger Single Six with two cylinders in the same price range. A Single Six with both cylinders was the first handgun I ever bought, back in the early 1960s, while stationed in remote Alaska in the USAF. While it is a fine weapon, the Single Six is NOT as much fun or as easy to shoot well as the PRM-30.