"Fire in the Hole!" is today used when events that cannot be altered are being set in motion.
It comes from mining / construction blasting when a hole was drilled in rock, and a charge of black powder (later dynamite) was inserted with a fuse. The warning cry "FIRE IN THE HOLE" was given when the fuse was lit. Fire from the fuse went into the hole and BOOM! Very logical.
"we're going hot"
Hot (and Cold) are widely used not just in firearms terms but also electrical terms and many other places. Hot (or Live) denotes active/operating/charged and therefore potentially dangerous.
These don't bother me. Really none of the terms (making sense or not) that were in use before and as I was growing up bothers me. What bothers me is current misuse or mis-definition of old terms and new made up terms used primarily for their "cuteness" effect.
There was one that bothered me in a thread a while back, one fellow identified the .257 Roberts as the ".257 Bob"
I don't care who you are, that's just barking
wrong.
Wheely /Wheelie to me is standing a car or motorcycle on its back wheel(s).
"Shotty" is just cutesy stupid sounding.
"Bottom Feeder" is mechanically correct for many repeaters, and I find it amusing, though the first time I heard it, I wasn't sure if they were talking about a gun, a fish, or a lawyer...
I never knew that the 1911A1 had a "dust cover" until I read it on the internet. There is no such part identified in any of the manuals. Its just the FRAME. An M16 or AR-15 has a dust cover, identified in the manuals and on the parts lists, a 1911A1 pistol does not.
You can call your front sight a "muzzle reference indicator" but its still a front sight....