My dad told me, that when he pulled guard duty in the US Army, circa 1962 at a base in West Germany, that he was sent out with a gun with no bullets. Much the same as now, the gun carrying was for theatre. So this is not a new phenomenon.
My brother was an AP in the Air Force from ‘64 to ‘68. He carried live rounds while guarding nuclear armed B52s. I wonder if that’s still the case.