Hey Vee! I'm am happy to answer your questions here. I only wish my artillery days weren't so far behind me!! 
On the video . They are slow in recharge.
If you time them from the firing of Gun 4's first shot to the second one, it is only 20 seconds. That is actually pretty fast. The other crew is only shaving 2 seconds off of that (they fire the second round 18 seconds after the first). The max rate of fire for an M-198 howitzer is 4 rounds per minute. This is assuming that there are certain safety checks (the section chief verification) that are not done. Another thing to consider is that the other video is is in a combat situation. You generally don't get that fast back home because of the safety considerations.
One question. The howitzer of this generation use a computer to set the coordinates??
We are all taught how to do manual gunnery. That involves some charts, special protractors, a book of firing tables, and the current meteorological information. The firing tables contain information to compensate for "non-standard conditions". What are the standard conditions? I'm glad you asked! From the FM-6-40:
STANDARD CONDITIONS
WEATHER
1 AIR TEMPERATURE 100 PERCENT (59° F)
2 AIR DENSITY 100 PERCENT (1,225 gm/m3)
3 NO WIND
POSITION
1 GUN, TARGET AND MDP AT SAME ALTITUDE
2 ACCURATE RANGE
3 NO ROTATION OF THE EARTH
MATERIAL
1 STANDARD WEAPON, PROJECTILE, AND FUZE
2 PROPELLANT TEMPERATURE (70° F)
3 LEVEL TRUNNIONS AND PRECISION SETTINGS
4 FIRING TABLE
So unless the Earth stops turning, you will never achieve "standard conditions".
Now on to your question, yes we do use a computer. Because the above process of manual gunnery is slower and less accurate than a computer, a special computer is used for this purpose. The current computer is the AFATDS (Advanced Field Artillery Tactical Data System).
It not only does the computations for the data to put on the howitzer, but it also helps control the batteries within an artillery battalion and even the whole fires effort for the battle. That means that the artillery liaison Marines/soldiers embedded in the infantry use the AFATDS to send the fire mission requests (calls for fire) to their supporting artillery unit. The artillery unit then decides to which battery or batteries the mission will be sent. You can also coordinate preselected targets from the infantry to the higher level arty unit to the firing batteries. It should be noted that the manual system of gunnery computation is still fast enough to be used in battle in case the automated system dies!
And how many men work for each gun ? A dozen ? Looks a little crowded, do they really have to be that many at a time?
The M-198 has a crew of 9 under normal circumstances. Of course "normal circumstances" happen about as often as "non-standard conditions" mentioned above. Usually the gun crews have to do with a less. 7 men (included the driver who, while not an artilleryman, can perform some of the less technical functions) is a minimum. The positions are:
Section Chief
Gunner
Assistant Gunner
Ammo Team Chief
Number 1 man
Number 2 man
Number 3 man
Number 4 man
Number 5 man
Yes, they are called "number 1 man" or "number 2 man", etc. There is a duty assigned to each number and these are known to all the members. The least experienced Marine (or sometimes the driver when the crew is up to full strength) is called the "Powder Monkey". During firing, this individual stands next to a pit dug about 10 meters from the gun where the unused powder increments are deposited. I should mention that the green bag and white bag propellants can have sections of the powder charge (increments) removed to have less powder in the chamber when firing. The second video had the crew firing 3 green bag. This means that two of the increments were removed.
The powder monkey holds the two removed increments in the air as another way for the section chief to verify that he is firing the right charge. He will look at the charge to be placed in the chamber, and then look at the powder monkey at the pit to see if he is holding the right amount of increments if any were removed.
I hope this is not a stupid question !
This would only be a stupid question if you were a crewmember of an M-198 howitzer for any time! Otherwise, I think almost no one would know this kind of info unless they were just a dedicated howitzer fan!
Stand by! Hook up! FIRE!!!
