AMT AutoMag II

AMT AutoMag II
Type Single Action, blow back
Place of origin United States
Production history
Manufacturer Arcadia Machine and Tool
Specifications
Weight 32 oz (910 g)
Barrel length 6 in (150 mm),
4.5 in (110 mm),
3.375 in (85.7 mm)

Cartridge .22 WMR
Barrels 1
6 grooves, right hand twist
Feed system 9 round detachable magazine

The AMT AutoMag II is the first of four semiautomatic handguns chambered in .22 WMR, the others being the Grendel P30, the Excel Arms Accelerator Pistol and the Kel-Tec PMR-30. It was manufactured by Arcadia Machine and Tool from 1987 until 1999.[1]


Designing the AutoMag

There were a number of engineering challenges to overcome in designing an autoloading .22 WMR handgun such as 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.

See also

References

  1. Dan Shideler; Jerry Lee (2012). 2012 Standard Catalog of Firearms: The Collector's Price & Reference Guide. Iola Wisconsin: Krause Publications. pp. 50–51. ISBN 978-1-4402-1688-6. Retrieved 25 May 2013.

External links