jump when fired. From this opening, a rather loud report is produced. A suppressor can only suppress noise coming from the muzzle. A suppressible revolver design does exist in the Nagant M1895, a Belgian designed revolver used by Imperial Russia and later the Soviet Union from 1895 through World War II. This revolver uses a unique cartridge whose case extends beyond the tip of the bullet, and a cylinder that moves forward to place the end of the cartridge inside the barrel when ready to fire. This bridges the gap between the cylinder and the barrel, and expands to seal the gap when fired. While the tiny gap between cylinder and barrel on most revolvers is insignificant to the internal ballistics, the seal is especially effective when used with a suppressor, and a number of suppressed Nagant revolvers have been used since its invention. There is a modern revolver of Russian design, the OTs-38, which uses ammunition that incorporates the silencing mechanism into the cartridge case, making the gap between cylinder and barrel irrelevant as far as the suppression issue is concerned. The OTs-38 does need an unusually close and precise fit between the cylinder and barrel due to the shape of bullet in the special ammunition (Soviet SP-4), which was originally designed for use in a semi-automatic. Additionally, the US Military experimented with designing a special version of the Smith & Wesson Model 29 for tunnel rats, called the Quiet Special Purpose Revolver or QSPR. Using special .40 caliber ammunition, it never entered official service. Automatic revolvers The term "automatic revolver" has two different meanings, the first being used in the late nineteenth and early twentieth centuries when "automatic" referred not to the operational mechanism of firing, but of extraction and ejection of spent casings. An "automatic revolver" in this context is one which extracts empty fired cases "automatically", i.e., upon breaking open the action, rather than requiring manual extraction of each case individually with a sliding rod or pin (as in the Colt Single Action Army design). This term was widely used in the advertising of the period as a way to distinguish such revolvers from the far more common rod-extraction types. In the second sense, "automatic revolver" refers to the mechanism of firing rather than extraction. Double-action revolvers use a long trigger pull to cock the hammer, thus negating the need to manually cock the hammer between