From what I read here and my own experiences (USN 1987-95) it's pretty hit or miss. Some military members (especially USA and USMC) really know their small arms stuff, others (USAF and maybe USN too
) not so much, with exceptions all over.
Back in my day, I thought the Navy's firearm instruction was a joke. I went a couple of years where the only shooting I did was me and some guys from my ship going to a range on our own time and dime with our own guns, because there wasn't enough time or $ budgeted to qualify everyone on our ship's small arms. The one time I was taken out to qualify with a 45 (1911), there was safety instruction but it was standard military instruction, geared towards the absolute lowest denominator. You know, 5 minutes of instruction on the 4 rules, crammed into an hour or so. I think the sailors on my ship were probably ok kind of safe, if not very capable with the small arms, but like a lot of people here seemed to experience, there were some of them I wouldn't have trusted with my neighbor's cat safety-wise.
My last two years I was an instructor at a shore-based unit, where even sea-returnee staff instructors weren't allowed (even me as a shift supervisor) to qualify on or carry weapons. No, that was allowed only for the security force, a bunch of knuckle-draggers if there ever were any. One morning I came into work and, walking across the quarterdeck of the command, there's a nice hole in the wall of the guard shack, about knee level, and another hole across the entryway from it. One of the brain surgeon guards who was protecting the place had an ND at 0400 and almost blew his foot off with his pistol. Luckily it was at 0400 or something and the entry wasn't full of people coming in for the dya. After that sand-filled clearing barrels went up and supposedly they weren't allowed to carry loaded weapons. But were us nukes allowed to qualify on the pistols? Noooo, just like a college campus, we were supposed to cower behind a desk or something while these lame security forces were going to come save us if the base got attacked (not likely in South Carolina in the early 90s, but still, you get the idea).