Some further thought food into it, and I expect these to be much more debated. Weapons can be "classified" just like ships, but it all depends on the way you fly them. A junker flown aggressively is completely different from a junker flown passively, even if the loadout is the same. Guns are completely different beasts depending on how they are used. My goal is to identify the classification of the weapon while pointing towards strengths it may have in other classes. Also, more generalizations about the classes, because it is fun. As always, feel free to discuss.
ARCs
[A] tends to be perfected by
timing. Guns and ships are coordinated to deal the exact type of damage needed at the exact time it is needed. Everything is optimized for quick kills where everything fires in perfect coordination.
[R] tends to be perfected by
gunner skill and
coordination. Reactive depends on the ships and guns reacting to the situation properly and making every shot count. Coordination is necessary for the ships to be able to support each other when needed.
[C] tends to be perfected by
piloting skill. Control ships tend to have much lower killing power and lower skill weapons. They depend on the pilot knowing exactly how to handle the ship to stay in control of the engagement.
Guns
Gatling - AR-C
The gatling gun shines as a DPS weapon, highlighted most often on [A] and [R] ships as an assistant to dealing rapid massive amount of damage. It depends on other weapons to deliver finishing blows, and so works best as a weapon on a ship with easy arcs to fire secondary weapons.
It has an additional point towards control due to incendiary ammo and component damage. The gatling gun can be loaded with incendiary ammo to cause chaos on another ship to increase your control over it, and it can be used to disable specific components, also assisting in control.
Mortar - AR
The natural mate to the gatling gun, the mortar shines as a DPS finishing weapon. It is a natural fit on [A] and [R] ships as a close range damage dealing weapon when properly supported. However, it does need piercing support, making it a poor choice for [C] ships. While it can damage components on its own, this ability is insufficient to gain proper control.
Carronade - C
The carronade is a pure control weapon. It rapidly shreds balloons, and can be combined with heavy clip to destroy individual components. It is a key weapon when playing with vertical control, allowing a ship to gain the high ground and maintain absolute control over the remainder of the engagement. However, it does not deal sufficient armor or hull damage to be appropriate as either an [A] or [R] weapon.
Flamethrower - C
The (current) flamethrower is also pure control. With the ability to hit every component it passes through (and even multiple ships at once), along with the chance to set fire stacks on everything it hits, the flamethrower slowly takes control away from an enemy as they are forced to leave guns to maintain their ship. However, it currently does not deal enough pure damage to qualify as either an [A] or [R] weapon.
Flare gun - C
The flare gun is a control weapon. The hit damage with 10 stacks of fire are reminiscent of the flamethrower: low damage and high chaos. This alone points it towards being control. However, the primary use of the gun is the ability to light up clouds, which does 2 things. First, it alerts you to the presence of enemies. This is critical in controlling an engagement. Not knowing where an enemy is can quickly lose the control. Second, it pushes the enemy towards where you want them to be. An ambushing team is less likely to attack through a flared area to avoid being spotted. This means that with flares you can (in theory) funnel the enemy into a location of your choosing for the engagement.
Harpoon - C
The (broken) harpoon is pure control. With low damage it does not fit either [A] or [R]. It can be used to pull the enemy into a position more favorable for yourself and less favorable for the enemy.
Mine launcher - C
The mine launcher is a control weapon. While it deals large quantities of damage, the most important factor of the mines is that they alter the location and momentum of the enemy. This allows a ship to take absolute control over an enemy, knocking off their arcs and preventing them from taking part in a fight.
Artemis - CR
The artemis, with its slow turn speed and high disable power, is good for controlling fights through key disables and for assisting in reactive dps. Less effective in aggressive builds due to its less than optimal explosive damage, it offers respectable power for reactive builds that intend to deploy more guns at once.
Hades - AR-C
The hades is a wonderful mix of DPS and control, offering the desired piercing damage along with the potential for fires and balloon damage. The piercing damage is effective for both [A] and [R] builds, and the fires help give control.
Mercury -
(CR)
The mercury is confusing beast. My best bet would be to classify it as control and reactive, though that is mostly based on gut feeling. The disabling ability of the gun along with the long range accuracy make it a good weapon for setting up reaction traps and controlling fights through disables of key components.
Banshee -
(C-AR)
I honestly don't know the home territory of the banshee yet. My best guess is as a harassment killing weapon, such as a gat-banshee squid. This would fit in as a C-AR style weapon I guess, though the explosive damage indicates it should be used as a DPS weapon. The fire it can cause is definitely [C] style with a hand towards actual damage potential.
Light flak - AR
DPS kill oriented weapon. The light flak's only purpose is to deliver explosive damage for killing blows. It currently fits as a mid-range finishing weapon on [A] and [R] ships.
Heavy flak - AR
DPS kill oriented weapon. The heavy flak's only purpose is to deliver explosive damage for killing blows. It currently fits as a mid/long-range finishing weapon on [A] and [R] ships.
Lumberjack - C-R
A control based weapon for popping balloons, the lumberjack has the unique property of having several times more ammo per clip than is needed to pop a balloon. This allows it to continue dealing damage even after its primary function has been served, making it a respectable reactive weapon: react to the opponent and retake control.
Heavy carronade - C
Similar to its light sibling, the heavy carronade it built for control. While it has hull shredding potential, well used carronades will help maintain constant control of close range vertical gameplay.
Hwacha - C-AR
The hwacha is a control weapon with a taste for damage. The primary function of the hwacha is to disable the components of an enemy ship. Proper use will take all physical control and power from an enemy, giving you the opportunity to position yourself as desired for a continuation of the fight. Additionally, the explosive damage potential of the gun allows you to deal killing blows at opportune moments.