Blast Chamber
The first and largest internal chamber of a suppressor, set just ahead of the muzzle to take the initial gas blast before the baffle stack.
The blast chamber is the open volume at the rear of a silencer, the space the bullet enters first after leaving the muzzle. It is deliberately the largest single chamber in the can, giving the violent slug of high-pressure gas room to expand and lose energy before it reaches the more finely tuned cones downstream. A larger blast chamber generally helps a suppressor handle hotter, higher-pressure cartridges without eroding its first surfaces too quickly.
Once that initial surge has spread out, the remaining gas flows into the baffle stack, where successive walls keep slowing and cooling it. The size and shape of the blast chamber influence both the sound reduction and the amount of back pressure the design sends rearward, so it is one of the central trade-offs a suppressor engineer balances.