Abstract: A method for adjusting a spacing of a leveling plate from a chamber body comprises attaching a mounting stud that includes a stud threaded surface to the chamber body. An adjustment screw is provided that has a first threaded surface threadingly engaged with the stud threaded surface. A bushing is provided that has a bushing threaded surface threadingly engaged with a second threaded surface of the adjustment screw. The bushing is movably coupled to the leveling plate. Coarse adjustment of the spacing between the leveling plate and the chamber body is made by rotating the adjustment screw with respect to the mounting stud. The bushing is fixed to the leveling plate. Fine adjustment of the spacing between the leveling plate and the chamber body is made by rotating the adjustment screw with respect to the mounting stud and the bushing.

Abstract: A firearm cartridge headspace gauge consisting of a threaded cylindrical barrel and threaded head is machined internally to precisely match the external dimensions of a given firearm cartridge. A scale is provided on the gauge barrel and mating head. When a cartridge is inserted into the barrel and the head is installed to the point at which the interior of the head contacts the cartridge, the scale may be read to determine any difference from the optimum headspace for that type and caliber of cartridge. Varous sizes of cartridge headspace gauges may be produced so as to conform precisely to the dimensions of any cartridge desired. The gauge provides a method of quickly and precisely checking the exact headspace of any cartridge, whereupon the cartridge may be resized as necessary after removal from the gauge.