According to an older copy of "The Blue Book of Gun Values", the S&W 422 was made from 1987 to 1996. One version had fixed sights (rear was adjustable left-and-right by tapping), the other was a Target Model with a click-adjustable rear sight like S&W offered on their revolvers. Plastic or checkered walnut grips were available.
I've shot several of these lightweight .22 autoloading pistols over the last couple of decades, and my experiences with them have always indicated they were reliable and fairly accurate. A friend who lived in Alaska used his stainless model (622) as a trapping pistol for several years, with good success. The only things that really stand out in my mind about these guns is the strange disassembly procedure (propping the slide partially open with a fired case), and the fact that whenever I shot one, I'd often get slightly toasted by a few grains of hot powder residue landing on the side of my trigger finger. The ejection port (where the fired shells fly out of the action) is very low on the side of the frame, and sometimes a few flecks of still-hot gunpowder would fall out of an empty casing as the gun would cycle, and if they landed on your finger, you'd know (and remember) it.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)