The Onyks features a bolt carrier borrowed from the wz.
This means that the gas alone impinges upon the bolt carrier.
The gas system, bolt carrier, and bolt-locking design were novel for the time.
Once the bolt carrier moves to the rear a small distance, excess gas is vented through holes in its side.
The bolt carrier continues rearward with the momentum it acquired in the initial phase.
The bolt carrier features an integral lug in place of the AR-15's gas key.
You only really have to worry about the spring, the bolt carrier, and the bolt.
Then the recoil spring and its guide fit in back of the bolt carrier.
The Stoner 63 has a unique buffering system contained within the bolt carrier.
The charging handle is welded to the right side of bolt carrier.