It the pistol people love to hate - but mostly by those who don't own one. They hear "pot metal" from someone on the internet and automatically write it off.
If you're expecting it to be a $1300 Walther PP in .22 LR, it's not, but for the money it's a decent .22LR pistol that shares the same basic design as the full size PPK/S and offers excellent reliability.
The sub assemblies are made a little differently, in line with price, but it's the same Walther design and operating system. The major difference is that it uses a barrel liner inside a barrel shroud held in place with a nut on the end, like the Walther P22. The barrel shroud however is press fit into the frame like the PP series barrels. The bolt face and barrel face are steel, and are quire durable.
The frame and slide are made from a Zamak alloy, and while most people consider it to be "pot metal", it's a bit of a misstatement. Low grade pot metal used for casting a variety of low cost items is well known for dimensional instability and cracking, but that's caused by impurities in the zinc alloy. Zamak alloys are held to very high purity standards and don't display the same cracking and dimensional instability issues. The Henry .22 lever actions have a Zamak receiver under the cover and they seem to hold up well as did the Ithaca lever actions that preceded them, and the Umaraex/Walther PPK/S should hold up just as well.
The lightweight Zamak alloy in the slide allows the slide to have a full PPK/S profile, but they make up some of the weight by filling in the area under the grips, which makes it feel much more like the .380 PPK/S. The standard grips are consequently thinner and can't be interchanged with the PPK/S grips. the standard black plastic grips are not all that exciting, but there are some very nice aftermarket grips for it.
The magazine extends below the grip into the grip extension so the finger grip magazine is the only option - no flush floor plate mags are available (yet?). There is also no loaded chamber indicator and the hammer is consequently not grooved to enable you to see it.
I've put a couple thousand rounds through mine and it's been very reliable and is about as accurate as you'd expect from a short barrel, short sight radius pocket pistol, giving about 3" groups at 12-15 yards. The double action trigger pull is typical PPK/S heavy, plus another pound or two, but it's reasonably crisp and clean and the single action pull is ok and represents the PPK/S fairly closely.
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Another option is an FEG AP22. They show up now and then in the $300-$400 price range and they are an all steel pistol using the Walther design. The slide however is thinned to reduce the weight so the profile is a little smaller. They are however very well made pistols.