The Hamilton Watch Company increased its production of precision watches following the entry of the United States into the Second World War in 1941. Its 16-size 992b railroad quality pocket watch formed the basis for their Watch, Navigational, Master, most of which, 73,285, found their way into Air Force use, while 21,1512 were assigned to the US Navy, with 312 going to the Royal Canadian Navy. The movement was designated 4992b. Between 1941 and 1969, when production ceased, about 140,00 had been made.While it retained the fine quality of the 992b, it differed from it in having a sweep second hand , a 24 hour dial reading GCT (Greenwich Civil Time) and a hacking function, allowing the movement to be stopped easily by pulling out the crown so that the time shown could be set precisely to GMT. It was also up-jewelled to 22 jewels.
Figure 1 shows the layout of the face. The case was generally of chromed nickel silver, though some early ones, made for the Navy, were of silver. Both the back and the bezel screw on. This watch runs well, keeps good time and is in excellent condition, as is the metal case, box and paperwork.There are several service markings inside the rear case back, but they are too small to read with the magnification instruments I have available. I believe the watch was serviced within the last ten years by my father's watchmaker friend. Everything looks to be new-old stock. The item "1941 Hamilton 22j WWII 4992B Army Air Corp Navigation Pocket Watch/Case GCT MINT" is in sale since Saturday, August 05, 2017. This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Pocket Watches\Antique". The seller is "monstrobuyer" and is located in Fresno, California. This item can be shipped to United States.