It changed by performing reconstruction of these this time. When the weight of a bolt or a buffer decreased, recoil decreased for a while.
However, reaction came to enter keenly by having shortened the buffer and the bolt. In addition, change does not have the amount of retreat of a bolt, and it decreases also in reaction and it becomes easy to control it.
Compared with a pure state, they are a little whether a discharge cycle is equivalent and the impression which went up. However, it is necessary to increase the number of times of discharge from now on, and to see progress.