i think we in the us have more advanced (and complicated) feed systems, while the russian system seems like its designed for simplicity. theres some pics and information
here, and they werent easy to find. the ammo drum is tiny compaired to the ones the we use. now im not sure if the ammo is stored helically or in coil fashion. the article says this gun can use either an ammo belt or a linkless feed system similar to what we use.
we use helical linkless feed systems on all our guns. theese are by far more complicated. they actually have a continuous looped conveyor belt that runs through the whole system including the helix within the drum. ammo in the drum is stored with their tips pointing inward twards the center. the whole system requires a rather complicated transmission all of which is synced with the barrel rotation. theres some good pics of both the vulcan , GSh-6-23, and many more
here as you can see the feed systems on the american guns are much more elaborate and have bigger drums.
