Do you mean whether you feed the 10rnd tubes front to back?
On mine, the plug can be pushed out and forced into the other end.
But it's not designed to feed that way ~ the feed is soldered on and holds more on one end, reversing the tube leaves balls rolling back & forth over the breech.
yeah that black plug. mine can be reversed depending if you want to rock the gun back or forward but I need more O-rings that are on that plug because its getting loose and falling out when bumped,,,, wondering if its the same orings found on tank regs.