Who knows what this gun used to be, but when you pull the trigger the bullets still come out.
The weapon alerts enemies (generates noise) in a 21 unit radius.
A very basic SMG that's good only as long as the Rangers don't find a better one. Replace ASAP.
"Greaser" is the well known M3 "Grease Gun". It was originally designed in .45 ACP to be a cheap replacement for an expensive "Tommy Gun". However, there were versions and conversion kits chambered for 9x19mm Parabellum.