Now we are talking about a subject that is close to my heart! When I finished my basic officer schooling (a combined 9 months) I went to artillery school at Ft. Sill. I spent 2 1/2 years as an "oh-eight" (08XX is the artillery occupation field in the USMC - 0802 is an Arty officer, 0811 is a cannoneer, 0841 is a fire direction Marine, etc.) I loved being on the gun line, but I only spent a short 8 months as a gun platoon commander of Golf Battery, 2d bn, 10th Marines. For the rest of my time in Golf Btry, I was either a forward observer or liaison officer (the liaison officer works at the infantry battalion HQ coordinating the observers who work at the infantry companies). After being the Guns platoon commander, I was sent to the HQ Battery, 2/10 to be the XO (for six months).
On to the video: It does seems like chaos here because these guys are in a real hurry as they are in a combat situation. Everything is actually going very smoothly (until the 47 second mark where it looks like the Marine inserting the primer into the "firing mech" is having issues to the consternation of the section chief.) What happens first is the commands from the Fire Direction center (FDC - they take the location of the target from the observers and turn that into firing data that can be put on the gun) are sent down to the gun. This includes shell/fuze combination, deflection (the left or right from the azimuth of fire) in mils vice degrees, the type of charge, and quadrant elevation in mils. They do not show this in the video. By the time we join the gun-bunnies in this video, they are already have the information and are firing as soon as they can get the rounds in and data set. In the video they say:
FPC(?) - this first command is garbled so I can't make it out. This is the shell fuze combination.
302 - QE (quadrant elevation)
Stick - this is a nickname for the M203A1 charge. It is called that because the propellant is contained in a long, one piece cardboard tube.
3188 - this is the deflection. This would be a little left of center line as the azimuth of fire, as it relates to the gun line, is always 3200 mils.
[The firing mechanism is primed at this time. The primer looks like a small, all brass shot gun shell.]
Hook up - the section chief tells the Marine to hook up the lanyard.
stand by - warning for the Marine with the lanyard to be prepared to pull it.
FIRE! - the Marine pulls the lanyard. With the recoil the way it is on a charge 8 (the charge number for stick propellant) you better be out of the way, when that thing goes off!
In this one you see a more calm firing of a M-198 at Camp Pendleton. The video quality is better and you hear better as well. In this one, you hear the commands coming down over the Vietnam era comm gear (seriously) to the guns from the FDC. At the beginning, you hear two rounds. What you have missed just before that are a few commands that are addressed to the whole battery. it would have gone like this: Fire mission, HEPD, charge 3 green bag, battery 2 rounds. After that, it would get into the data for each gun. They go gun by gun, so the gun here, number 4, waits for thier data. Since the guns are obviously geographically separated, the firing data will be different for each howitzer. Since the FDC did not say at my command, the guns are free to fire their two rounds as the are able. While the gun waits for its deflection and QE, it prepares the right fuze on the right projectile, and readies the propellant. Gun 4's data: Gun 4, deflection 3364, the gun repeats back the command, quadrant 317, the gun repeats back the command. As soon as they get their deflection and QE, the section chief checks the shell/fuze, QE, charge, and deflection. As he approaches the Marine with that duty, they shout out the data he is checking, he then repeats the data and adds "verified" if it is correct.
Now, you want to see real chaos, you should watch a howitzer being emplaced! The line of fire will be marked by the advanced party by engineer's tape (actually more of a ribbon if you are unfamiliar with the stuff). The truck drives the opposite direction of the azimuth of fire (the back azimuth of fire or BAF) and just as the truck slows down, things start flying out of the side of the truck. These are things that can't break i (in most cases) like buckets, shovels, picks, etc. When the truck stops, the gunner and a-gunner (assistant) run down the trails to their positions and start screwing on the sights for the QE and deflection. The trails are unhooked and everyone busies themselves with their particular duty. I watched numerous emplacements and I think I saw someone almost gravely injured every single time but no accidents occurred at those times. There are lots of ways to hurt one's self, believe mw (lots of moving heavy objects) but none ever happened upon emplacement. Sorry, no video!