While it’s somewhat well-known that the Soviet Union produced special-purpose silent cartridges for clandestine use, but less well known are US experiments in this area. In fact, the US developed several weapons, and several different types of ammunition, for suppressor-less silent operation (including silent shotgun rounds). The document we’ll be looking at today is accompanied by several other scraps of information available on the Internet, and is called Silent Weapon System Cartridge Design and Development. It covers post-war cartridge designs and their analysis. Supplementing this, we have a short history of pressure-sustaining cartridges available on Scribd (an Overview of the Design and Construction of Pressure-Sustaining Small Arms Cartridges, by David Tucker), as well as a US patent for a pressure-bearing silent cartridge, pictures of the Silent Weapon System rifles on The Unwanted Blog, pictures of US silent cartridges at IAA Forum, and another DTIC document on the math behind silent cartridges.
Silent weapons are not my focus, and so I won’t have any commentary on these documents. If they interest you, though, they should make fascinating reading!