RWNJs are hooting and screeching over this. This kind of error, a trivial slip of the tongue to sane people, is a major offense among ammosexuals. Dick Durbin Says No Self-Respecting Sportsman Uses an ‘AR-47’ to Hunt Deer in Illinois

These pedants need to check out the log in their own eye. I wish I had a dollar for each time I have heard some ignorant, but self-assured, gun humper declare authoritatively that “AR-15 is the semi-automatic version, while M-16 is the full-auto version.” Not true. AR-15 (“Armalite rifle, design 15”) is the civilian, commercial designation used by the weapon’s original manufacturer, Armalite, while M-16 is the official military designation. There are both fully automatic (“select fire”) and semi-automatic AR-15s. Many AR-15s were used by US forces in Vietnam, the Air Force and Special Forces, before the weapon was adopted as standard issue and given the military designation M-16. These were all select fire. My father (who was in the Air Force) had one in Vietnam in 1964 and thought very highly of it. By the time I arrived in that stricken country in 1971, it was the M-16 and few GIs knew what an AR-15 was.

Addendum: “AR-15” is a registered trademark of Colt (which bought the rights from Armalite) to this day. The semi-auto AR-15 has been marketed to civilians since 1963, though few had heard of it till fairly recently.