G36 FTW wrote:You could use the guts of a airsoft M249 stuck inside of whatever box magazine you have attached to the 1919.
The issue isn't "What internals would I use?"
It's more of "How would I get the bbs inside the hopup chamber and a fast enough rate to match the fire rate of an M14 with an 11.1V li-po"
And speaking of speed, I don't think a gravity fed hopper would feed fast enough to have that high of a fire rate -.-