This spring is mounted to the point(s) where the firearm contacts a mechanical holder such as a tripod or human upper torso.
More sophisticated designs use hydraulic[2] or pneumatic shock absorbers;[3] systems of springs, cams and levers to modify, dampen, or dissipate the rearward impulse generated as the projectile is fired down the bore of the firearm.
Aftermarket buffers are often moulded bumpers or additional springs placed between operating metal parts which impact one another, such as the slide and the frame of a semi-automatic pistol.
When compressed, they present initial resistance as the rod-to-seal grip is broken and then they move in a regular manner.
[citation needed] There is some debate as to whether or not buffers really reduce recoil, with some arguing they actually increase it and, in addition, cause malfunctions of the firearm.