Comments by "geodkyt" (@geodkyt) on "The Sneaky Silent Sten MkII(S) at the Range" video.

You can't lock the bolt, and you can't really cushion the bolt closure, because it is an open bolt gun. That bolt has to be moving with enough energy to strip and feed a cartridge and fire it with the fixed firing pin as the bolt closes. With a hammer or striker fired closed bolt.gun, you can effectively turn it into a manual action where the bullet impacting the berm 100 yards downrange is louder than the click of the firing right next to your ear (BTDT). Now, if you're getting significant noise from the recoiling parts hitting the back of the receiver on the opening stroke, you could buffer that (which many non-suppressed guns, both open and closed bolt already do, just to reduce felt recoil, reduce rate of fire, or decrease receiver wear) and reduce that mechanical noise. This Sten is about as quiet as one can get an open bolt gun.
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@discerningscoundrel3055 a friend was testing a .300 Blackout Remington 700 with an integral suppressor he had just built. Thumbing rounds into the magazine was literally louder than the sound of the gun firing.
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