The "Swedish K", produced by the Carl Gustaw company, designated the M45, was a 9mm SMG. It was very popular with Special Operations types in Vietnam, but the Swedish ceased importation of it because they opposed the American invovlement in Vietnam, leading S&W to manufacture the 76, which was a copy, but superior in a few regards.
NRA Life Member
Me: "The .45 GAP was an answer to the question nobody asked."
Trooper pal: "Says the guy who thinks .38 Super and 10mm are viable pistol calibers and gets mad when Wal-Mart doesn't have them."