I know this will offend some of my fellow retired LE officers and veterans. but being, or having been, A police officer, soldier, marine, seal, green beret, "Mall Ninja uberkommando," chinese tong member, or whatever does not automatically make you an EXPERT on small arms.
I knew a guy a few years ago, who was a police sergeant, and held a "Master" rating in NRA pistol bullseye competition, who didn't know that the M-14 and M-16 fired different cartridges!
I met a retired marine, 30 years service, that thought the 1903 Springfield was a .30-30.
And I've known literally DOZENS of active duty military who thought that "getting hit in the hand with a Colt .45 automatic would spin you around and throw you to the ground so hard that it would leave you unconcsious.
So much for experts!