Destin Sandlin, the former Army engineer behind the YouTube channel "Smarter Every Day," shot video of see-through suppressors and then went through the video in slow motion, discussing exactly how these weapon accessories work to mask the location of a shooter.
Suppressors are often referred to as "silencers" in popular media, but that's a misnomer that has been clearly debunked in the last few years. So let's take a quick look at what it does instead of silencing the sound of the weapon.
When a weapon is fired, a pocket of cool air and powder is suddenly ignited, creating a massive stream of extremely hot gases that propel the round from the barrel. This process also creates an audible explosion that can alert everyone in the area as to where the shot came from.
Suppressors work by channeling the explosive gases through channels, often cut into a series of chambers, in such a way that the gases escape over a longer period of time, mostly after they've already cooled and returned to normal volume. This doesn't eliminate the sound, but instead turns it from a solid single explosion to a sort of muted thunderclap with a short roll to the sound.
Typically, this process takes place inside a metal "can" that contains the suppressor, making it impossible to see the flow of the gases. But as this video shows, high-quality acrylic can serve the same purpose, allowing you to see the flow of the gases. The best example is the second demonstration in the video, and you can actually see the process in its stages.
First, the suppressor captures the gases leaving the barrel in a large chamber near the muzzle. But then, as that superheated gas is captured, the suppressor channels a lot of the gases over a diamond-patterned area which contains the heat until it dissipates. The gases don't escape until after the bulk of the heat is gone, making the sound much quieter.
Of course, this process does have some drawbacks. First, a large amount of heat that would normally pass into the air is instead captured in a can near the barrel, increasing the amount of heat that remains in the barrel. This shortens barrel life and reduces how many rounds a shooter can fire in a short period of time without melting the barrel.
It can also affect the ballistics of the round fired and the accuracy of the shooter as it changes the flow of gases and adds weight to the barrel.