This is my new Sten. There are many other like it, but this one is now mine...

[Bruce_in_Oz]

Yep!

All of that energy has to go somewhere! '"Wet" cans are an interesting study in themselves. Otherwise, you have to get rid of the heat via the mass of the muffler itself; as it heats up, it basically becomes less efficient, because part of the way a proper can works is by essentially cooling the gases and slowing down their entry into the atmosphere.

Then again, who is likely to still be "clandestine" after expending several mags of 9mm, even with a decent muffler? The "smack" of bullets striking, even at sub-sonic velocities, is not to be ignored, never mind the rattle of the action and the "tinkling" of the spent brass.

"Silent" they ain't: the whole point is to "diffuse" the muzzle blast that is the rather distinctive signature of "normal" shooting.