AMT AutoMag II Gun

History about AMT AutoMag II Gun and some Facts, AutoMag II Gun is one of four autoloading handguns chambered in .22 WMR, the others being the rare Grendel P30, the Excel Arms Accelerator Pistol, and the newest, the Kel-Tec PMR-30.
Arcadia Machine and Tool was a California-based gun manufacturer that was sued out of existence back in 1999. The city of Newark, New Jersey sued AMT along with 28 other manufacturers and distributors in June of that year, following a lawsuit filed by the state of California filed in May. Faced with mounting legal costs, AMT went out of business shortly thereafter. Recently, the Crusader Group Gun Company, Inc. of Houston, Texas, acquired the brand from Galena Industries and is marketing it with their line of High Standard firearms.
There were a number of engineering challenges to overcome in designing an autoloading .22 WMR handgun. Not the least of which are extraction problems. The extraction problems stem from the fact that the slow burning rifle powder of the .22 WMR cartridge develops a late peak pressure. This can cause the case mouth to expand and jam in the chamber when fired from a handgun. AMT overcame this issue by drilling 18 holes at 90 degrees to the chamber. A sleeve was then welded over the chamber; providing a tiny amount of clearance for the excess gas to escape from the first set of holes on back to the second set, thereby relieving the pressure enough to prevent the case from sticking. The stainless steel slide has a large cutout over the barrel, similar to the Beretta M9, to facilitate better cooling and ejection of the spent brass casing (more likely it is simply to reduce the moving mass of the slide to allow for the blow-back operation). The stainless steel construction throughout makes rust a non-issue.