Never take for granted that people know about "popular usage"
Free Republic postings here show up on Google, so anyone who does not know, but earnestly wants to learn, could easily end up at this very forum seeking information.
Because of that, I believe clarity is needed when describing the difference between the actual machinegun often called Ma Duece by soldiers, and the cartridge itself.
Several here have it right, the business about .50 BMG is to ban/confiscate rifles that have never been used in crime, just to advance a gun confiscation agenda that will be expanded one victory, one sliver of the shooting sports community at a time.
Agreed, on all points.