Over the years several companies have put 22 mag semi autos on the market in both handguns and rifles. Almost all are a blow back design. That means the weight of the bolt and spring resistance has to hold the bolt closed long enough for the round to fire, pressure drop from peak pressure to a reasonable pressure. Then open the bolt, extract, eject the case cock the action and reload another round in the chamber. In a perfect world all Ammo would run the same pressure and the pressure peak would follow a pressure curve. We do not have that with bullet weight running from 30 to 50 grains and where each ammo spikes on the curve being different. As an example the 17 hmr and 22 mag have the same basic case because the 17 is a necked down version. This is done a lot with centerfires. Using a gas operated system is standard with centerfires. The bullet passes a hole in the barrel gas is bled into the gas system where the gas pressure operates the action. This design works with a wider pressure range reliably. It also operates with Ammo that is running much higher pressure than rimfires run. The problems with blow back are multiple. The bolt opening too soon blows cases and usually rips the extractor off the bolt. Actions tuned for the rounds that spike the quickest will not cycle ammo that spikes slower and they may both reach the same pressure. When the 17 hm-2 came out it ran the same chamber pressure as the 22 long rifle. Logic said any action that would handle the long rifle would work with it. Yet the pressure spike for it was just that, an instant spike that would open actions so fast the chamber pressures blew case heads and did all kind of other things. Weight was added to bolts, heaver springs used and companies gave up on it. The 17 hmr and 22 mag share many of these problems, with the 22 mag it takes a little longer fot some problems to show up. The Ruger 10/22 mag developes action problems, things crack and break. I am not a semi auto fan but own and shoot a few. It is possible to fine tune the 22 mag and 17's to run in semi autos. It usually requires tuning to one brand of ammo with one weight bullet. Companies are in business to make a profit with as few problems as possible. The companies that make them now usually give a list of what their gun runs with.
