Made in Canada, this S&J Hardware, this Carbine Buffer is one of many pieces that helps your rifle to operate normally. When a bullet has fired the energy that it released pushes the bolt carrier backwards which then connects with the buffer within the buffer spring and tube. At the point of contact, the buffer pushes the spring backwards. Depending on the weight of the buffer and the strength of the spring the buffer will reconnect with the bolt carrier pushing a new bullet forward into the chamber to be fired.
One of the great benefits of a properly matched buffer and spring is the ability for the combo to reduce recoil!