It was quite common for naval guns of 6" and greater for then to have separate shells and power charges. This was basically the same gun used on the Omaha class CL. With a 105lb shell and a 44lb propellent charge it w be pretty hard to man-handle as a single piece.

Not sure, the wikipedia artical for Nautilus said that on her second war patrol she I don't know if a patrol boat counts as a warship.

USS Narwhal (SS-167)

The twelfth war patrol – from 10 June – 7 July – gave Narwhal a chance for some action. On 13 June, she submerged for reconnaissance of Bula, Ceram Island, a source of enemy oil. That night, the submarine closed the shore and fired 56 rounds of 6 in (150 mm) projectiles to destroy several gasoline storage tanks and set fires around a power house and pumping station area before she had to retreat from the salvos directed at her.



She spent her second war patrol – from 28 May – 13 June – in defense of Midway Atoll. As TF 16 – with the aircraft carriers Enterprise, Hornet, and Yorktown — prepared to meet the Japanese attack, Narwhal joined Plunger and Trigger in scouting east of Midway; during the Battle of Midway on 3–6 June, these submarines – along with 15[13] others – accomplished nothing.

==================================

My mistake on this post. I misread a description of Nautilus and was instead reading Narwhal. I'll get that brain scan and my glasses checked soon LOL.

The separate powder bags was common at the time that the subs where designed and constructed which was the mid to late 20's.At one time all shells even smaller size ones where not fully in cased.And guns past a certain size where usually powder bag.The 6 inch guns used on the V class boats was simply a modification of a surface gun.I am fairly sure during WWII in any navy any gun over 6" had powder bags.

A site that I really like to look at and I am guessing you will as well is http://www.navweaps.com/
here is the page for all US Navy guns http://www.navweaps.com/Weapons/WNUS_Main.htm

Remember that the V class where designed when it was expected that submarines would stop and search a merchant remove the crew and any passengers then sink it.:har: No seriously they really agreed to this in treaties the UK actually tried on more than one occasion to completely ban subs.The V class where never designed to attack a warship on the surface.

Early in the war before the SJ radar was available they had to use only optics and estimate range and such.The SJ radar could actually see water splashes created by shells hitting the water it could also see land small island and such.They would use the SJ to get a good range and use the splashes to tell how short or long they where.

The small size of a sub even the larger V class made them very unstable gun platforms as a result they usually only used the guns a close ranges 2,000yds or less.

Later in the war tey actually did have "gun boats" which had two of the 5"/25 guns one bow and one stern and a gunnery computer I do not think any of these entered service in time to see much action.A few boats did patrol that had the two 5"/25 but no plotting computer for them.

Are playing any of of the Mega mods? Trigger Maru Overhauled makes the deck gun a bit less stable than stock but Real Fleet Boat wins out for having the most realistic deck gun aiming movement greatly effects accuracy you can see the boat movement in the sight and you have to wait for just the right point to fire other wise the short will be short or long.
You can probably edit some files to make the TMO deck gun be more sensitive to movement although what you would need to tweak I have no idea.

Well, I know either TMO or Traveller's mod makes the ship rock quite substantially, making many shots go right into the drink or sail hopelessly high.

I just last night went into the deck gun sim files and significantly scaled back the reload times of the guns (which had to be way too high) and greatly reduced the gun traverse and elevation speeds.

I know this won't make it realistic (still was able to pop up in front of a Nomi-class patrol boat and rip it to shreds without it ever landing a hit), but it should help to make it somewhat moreso.

It must be Travelers because I do not run that particular mod.With TMO there is some sway to deal with but it does not have much of any effect on my gunnery.It seems to effect the AI accuracy though.I usually man the deck gun manually unless I have a small target and the 40mm bofors I'll pop him with that and allow the crew to use the main gun.

That Narwhal must have tougher damage than TMO and Travelers allow I am suspecting because with TMO even the Japanese 25mm shells will put a hurting on you and I know that Travelers increases damage effects.It obviously works with the two but they are not changing the damage models like they do with the other subs.

Not sure on the damage yet. So far I've only been hit once and it didn't sustain critical damage.

That should be a sign right there.A shell hit should cause serious damage.Even a couple of 25mm rounds should do damage.

Not sure what I was hit by, because it wasn't the "big boom" and shake typical of a shell hit but one of the crew yelled that we were taking damage and the bow tubes were out of commission.

Well based on what you say the Narwhal is not effected by the changes that TMO and Travelers makes.Someone would have to make a patch to have the Narwhal have the same damage modeling.

TMO alone makes the prospect of a surface gun battle a risk which it really was.Travelers increases the damage a bit more.

That may be so. I'll have to test it out. However, running the same mods, the S-Boat I was in prior to the Narwhal could take a few hits on the surface. Maybe I just got very lucky in it.

I do not recall with RFB it has been a while since I played it but with TMO a solid burst of 25mm at closer range ~2,000yds can knock down your hull by 1 point and will certainly kill crewmen on the deck if they get hit.

Lately I have been playing Op Monsoon and I think the rate is about the same.Though I have had damage to components on the top side of the hull even from the .50cal and 20mm cannon.

I notice that the AA gun fire is only really dangerous at close range I just zig zag and stay at least 4,000 yds away from a ship that only has AA and they almost never get any hits or only one or two and that seems never to do any damage.Seems for me regardless of the boat that cannons require several hits something like 8,9 or 10 to knock down 1 point of hull I used the term burst loosely meaning the numebr of shells in burst form an AA type weapon not so much that it literately had to be so many in a row.

I have no idea how harsh the 3.7cm and 40mm cannons are I have never been on the receiving end of either.

I am sure that you are correct about the guns having the same effect across their range which is why I stay out of the of AA because they have minimal accuracy that far out.I am also guessing that all "AA" automatic cannons are the same (20mm,2cm(German) and 25mm). The 3.7cm and 40mm bofors guns I bet they both have the same damage modeling.