Usually when people want a silent firearm they take an existing weapon, fit a suppressor and use cold loaded ammunition to make it quieter. Sometimes they build a weapon from the ground up to be quieter and get something like the de Lisle carbine. These are the common strategies and they both work … to varying degrees … but very rarely suceed in completely silencing the gunshot.
For that, you need something like a silent cartridge. These are rare beasts, complicated to engineer and usually more trouble than they are worth, but a useful technology to possess. The Soviet Union has particularly fond of them and came out with several designs which should be considered typical of the concept.
Broadly, a typical silent cartridge design operates by trapping all of the explosion from the round within the case - when the propellant fires it drives a piston, which expells the bullet from the case and then seals the gap behind it, ensuring that no gas escapes from the cartridge. Thus there is no blast, no flash - no sound at all except for the sound of the weapon's action and the passage of the bullet … and a subsonic bullet will be virtually silent in flight.
The Soviet S4M derringer is a classical example - and application - of the technology: - a two shot, break open weapon that fired the bullet from a 7.62mmWarPac round from a silent cartridge along a barrel designed to leave rifling marks identical to those of an AK47/AKM. This would leave anyone examining the body of someone shot with the weapon in question with the impression that the dead person had been hit from a long distance with an AK (due to the low impact velocity) rather than very short range with a pistol. Only of very limited use, but very useful in a limited field. Having developed the technology, the Soviets used it in all sorts of things, including the NRS-2 commando knife.
One of the wierder silent cartridges to be developed was the American M463 - a 40mm round, originally for the M79 grenade launcher which was fired almost silently and without smoke or muzzle flash by the abovementioned piston system … and effect somewhat spoilt by its high explosive payload, but at least the weapon could be fired at night, leaving the enemy with only a mysterious explosion to let them know they were under attack.
Game and Story Use
- The S4M is worth noting in its own right, especially for a CSI style campaign … and the design philosophy could easily be resurrected by someone else with forensics experts to annoy.
- Mossad would be obvious suspects, except they generally like their targets to know who has just attacked them.
- A silent cartridge/derringer combination would likely make a good assassination or insurgency weapon, designed either to eliminate a target in (relatively) secure locations or to allow an insurgent to quietly eliminate an enemy soldier or policeman and accquire his weapon.