Shell weight effect on penetration

[P3D]

Just made some calculations on the effect of shell weight on penetration. Same gun (same muzzle energy) but different MV due to larger shell.

Observations:
Shell weight maximum is ~30% larger than SS default. The maximum I got with scaling th US 16" 2700lbs shell.

Taking everything into account, belt penetration is comparable within 20ky unless at very close ranges. The difference can be assumed to be negligible.
Deck penetration is a bit different. A 20% heavier projectile could get the same penetration at roughly 20% shorter range.
That's very good news for me, as I could lump all shell weights for a given gun (bore and barrel length) and shell type together and make calculations for a moderately heavy shell.

[Borys]

Heavier shell more accurate

[P3D]

Actually lighter shell->higher speed->lower trajectory->better accuracy.

[Borys]

heavier shell -> less affected by wind -> better accuracy

[P3D]

Borys, you made me smile. We are speaking about half-ton projectiles here, not bullets from a pistol. The wind drift difference between a 850 and 1000lbs shells are minimal - the latter would have roughly 15% less drift, say, 17yards instead of 20 at 10ky at a 10kts lateral wind.

See Range Tables at the bottom, esp. columns 13 and 16.

[Borys]

Ahoj!
Every little bit counts :)

Those 3 yards might be the difference of hitting the magazines or the ice cream machine!

And just you wait for my 3000 pounders!

Borys

[P3D]

If the guntables account for wind speed, don't you think correction factors can be applied regardless of shell weight? If the gunnery people think it is so important...:P

[Borys]

Ahoj!
And how do you know which way the wind is blowing 10 miles away from you?
:)

Borys

[Tanthalas]

STAY AWAY from my soft serve Machines ><

[P3D]

Ahoj!
And how do you know which way the wind is blowing 10 miles away from you?
:)

Borys

Assume it is the same as where you are. My point is that any accuracy gained by smaller lateral drift is minimal compared to the effect of the lower trajectory.

[Sachmle]

I always figured the French had the ice cream machines on their ships.

[Borys]

Ahoj!
Well, several navies thought otherwise :)
:)

Schmle - one US ship was saved by the ice cream machine deflecting the shell ...
Borys

[Sachmle]

I scream, you scream, we all scream for Ice cream!!! ;D

[P3D]

Ahoj!
Well, several navies thought otherwise :)

I'd like to see a quote saying that the main reason behind the larger shell weight was smaller wind drift, as you allude. Anyways, the difference is so small that negligible in Navalism.

[Korpen]

Ahoj!
Well, several navies thought otherwise :)
:)

I think this is related to muzzle velocity; a lighter shell spends less time in the barrel, so there is a larger risk of incomplete combustion.

A heavier shell at lower velocity also give a longer  barrel life.