Russian noiseless cartridges

[SDC]

Actually, PercyShelley, the US produced shotgun shells during Vietnam that functioned through standard pump-action shotgun and functioned the same way that the US and Russian pistol rounds do; they use a folding metal membrane inside the shell to seal the propellant gasses inside the shell, so the only real noise produced is the racking of the action and the falling of the hammer.

 

[max popenker]

To add some diversity - how's about integrally silenced underbarrel grenade launcher?

 

[GaryL]

I wonder how hard it would be to get a shotgun to work along these lines.

That's already been done. The barrels are something like 7' + long. Might not be practical for home defense, but noise probably isn't that big an issue in that case.