- .177, .20, .22 or .25 cal., field target and hunting air rifles with high recoilless power without resorting to precharged gases or pumping. The model numbers, ranging from JW50 to JW80, indicate the piston stroke in millimeters. Smaller stroke guns usually are cocked by two stokes of an underlever. Larger stroke guns (70/80 mm) use three strokes. The large JW80 version, which requires an FAC license in Britain, produces up to 28 ft./lb. ME in .22 caliber and 30 ft/lb. ME in .25 caliber, blued or silverized steel finish, sporter or thumbhole stocks, action design, and standard or match trigger. 15 in. polygonal rifled barrel. About 450 rifles produced, most stocked for field target. Estimated about 2/3 sold into USA. Sporting stock versions about 9.8 lbs; thumbhole versions about 10.5 lbs. All guns hand built by John Whiscombe. Mfg. 1987 to present.