That there is a Puckle gun. Which was the precursor to modern autocannons. Which other members have mentioned here being, the pom poms. This is the QF1. The first pom pom:
It was a design used all over the world but saw it's first major use during WWI.
Now this weapon is not new to the GOIO forums. Others have posted it. So I'm just bringing their idea back and posting a way it can fill a spot immediately in game right now.
Proposal is for a single barrel semi auto fire light mount gun that serves in the mid range kill role that is vacant with the moving of the light flak up to long range. I don't count the banshee for this range as its more of a ranged flamethrower. Also, it doesn't shoot fast enough.
So, damage type...simple: Explosive
Range: Short - Medium. Max probably around 500-700.
Rate of fire: High
Spread: Triple shot semi auto with bullet spread.
Clip: 9-12 round. Mortar style rotating drum. So 3-4 bursts before reload.
Reload speed: Mortar speed would be reasonable.
Damage potency: Between LF and Mortar.
Bullet speed: Light Flak level speed
Jitter: High
Time between bursts: Debatable. 1-2 sec.
The purpose of this weapon would not be to replace the mortar or the flak, but to serve a role that the old light flak left open with it's move to long range play. For a quick hitting weapon that could generally land shots well in the short ranges but poor as the distance increased. Perfect for side mounting like on Squids, Junkers, Goldfish. Potential viability on Spires and Mobulas too. Any ship where arming timers are liabilities and getting mortars to unload fast enough is problematic due to the vessel needing to turn to make it happen.
Ammo must have a spread to it. So it fires 3 shots with spread. Heavy Clip maybe can resolve this but ultimately it would be a weapon more effective at quick strafing runs. Why 3 shots? Because we don't have a semi auto gun in the game. The gun would have to have a good kick to it due to firing 3 shots at a time. Hence the reason for the spread and the jitter. Aim may need to be reset after every burst.
Alternate firing mechanism...air. Similar to modern paintball guns. Pressure fired. Believe me, you can turn up paintball guns and shoot through wood with them. Also folks these day do use BB guns to hunt at times. Granted this is for a cannon so the pressure would be nuts. But the gun could add all sorts of leaky hoses and gizmos for visual effects.
So, thats pretty much it. Debate away! The one factor that is completely off the table and will never be considered for this weapon...arming timer. No, just no. No more timers. Defeats the purpose of having a weapon like this.