Just in case devs did not notice or forgot about my older posts.
And what seems rather wrong with them.
Frontal 6 barrels gun shoots with 100 pen, something like 16 bullets total. 2,5 bullets per barrel.
Side guns that seem possibly 300-like pen heavies are only considered medium guns. 200 pen. Guns shoot 4 bullets each, 8 total.
In comparison, Harcka heavy Cruiser has 5 turrets and each shoots 5 bullets. 25 total big fiery tracers.
Corsair gun firing animation is rather underdeveloped. Bullets Smol
Tracers long past their use
Or in case there are no tracers, and Pirates aim by estimation only, they aim by the smoke trail and impacts just in case they ever hit something 
Regarding the ships muzzle bores, the calibers, they would have very few ammo Something that looks miniscule is the pirate rogue frontal gun. But it is like the only gun that would really fit.
If I looked correctly, PD turret has a thicker caliber, than frontal Rogue static gun. I mean I did compare that one to the scaling of the barrels on Garda - the flak and the big bore of the Mk II Garda. Again, compared to much of the rest of the guns that are used, while Mk II does look modest, it is already HUGE.
And only then we are getting into big huge calibers that are the corsair side gun turrets and their armaments, which would provide a huge amount of recoiling force so as to be sending the ships in full backward motion.
So, while I describe the huge sizes of the guns, their huge calibers, while they do look cool, from a 'realistic'
point of view, the sizes remind me of something, when looking at Heavy Autocannon turret on Harcka, as something like at least 420 mm in caliber.
https://en.wikipedia.org/wiki/42_cm_Haubitze_M._14/16?ysclid=mdkdbmttw8741454108
Imagine you have an autocannon firing 1 tonne shells 
That is if the caliber is only 420 mm and fires ammo from ww1.
something similar in 540mm-600mm caliber from WW2. with less range. Despite caliber increase it didnt look like a marvel of engineering anyway, ballistics-wise it looked like quite a disaster btw.
https://en.wikipedia.org/wiki/Karl-Gerät?ysclid=mdkqof6sa1480484875
Meaning, huge ammo takes a lot of space and requires a more energy to propel than lighter ammo being thrown out of a less powerful gun. Super-light ammo without air an be propelled to astronomical speeds. When a big mass is thrown at huge speeds, it will be more dangerous of course.
While it might not look as epic if you thought of thinning out/lengthening the guns - smaller caliber, needs more volume to burn powder up compared to a larger bore.