I stood QD watches as a Junior Officer starting in the early 70s. Only the PO of the watch carried a weapon. In boot camp you fired 28 rounds of 45 ammunition. At OCS we fired probably twice that amount. After that there was no more small arms training. When I was based in Norfolk, it was just about a monthly routine for somebody to fire a bullet into the QD shack overhead while relieving the mid watch. Back when we had Security Guard Force on small boys to protect special weapons, those guys were relatively well qualified with the 45. Sailors in general were poorly trained in small arms.
One time I had the XO fall out the SDF in formation on the cruisers helo deck and I did the standard Marine thing of going from sailor to sailor to inspect their M-14s.
You know the drill: I go to the first man, first squad and he brings his rifle to port arms and I snatch it from him and go through the ritual of looking through it and checking for cleanliness and operability while quizzing that sailor.
Not this time. The first sailor wouldn't let go of his rifle and I had to tell him to let go of it to end the tug of war we were in. I looked the rifle over and it was slathered in oil and the sailor in question didn't know anything about it at all. I went to the next sailor in my ritual one step, left face in front of him. I snatched the rifle and when I did, the flash suppressor went sailing off the edge of the helo deck, bounced once and ended up in the sea. I was startled into silence for a second and I asked him if he had ever seen that rifle before and he told me that he hadn't - he'd just been handed that rifle 10 minutes before I got there.
I called off the inspection and spent the rest of my time teaching all those sailors how the rifle worked and how use it in case the ship was attacked.
Nice young guys, but clearly not trained in any way before I got there.