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Penetration and gun rebalance - review

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11 hours ago, Jan van Santen said:

Here is the full experiment (German) and it shows that a cannonball did not penetrate lo/wo  even at a 15 distance (starts at 30 mins)

Quick addition: They did scale down both the frame and the cannon so that the frame was only 20cm thick. That means that the cannon represents at least an 18 or 24pd cannon which is quite an impressive result for the live oak frame 

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Posted (edited)

in this issue of penetration and gun rebalance, it is only needed a little fix in my opinion, specially in the question on mast thickness wich is to buffed i guess in some ships. For example, a standard Victory DLc of seasoned live oak with french rig is almost indemastable (i have one DLC vic with 177 thick on mast and no ramndom mast bonuses, only a french rig), only double charge perk on 42 pdr shoots can demast at 50 meters. I had a battle some days ago redout vs redout in which i make more that 25 mast shoots in first mast with my long 36pdr and no efect. I ask the other player and said me that he was seasoned live with mast and rig 4 and no more mast bonuses... And imposible to demast, mast thick is 168. This is too much and needs a fix. But put the penetration of 24 long pdr on almost 200 is too much. And i am not discussing about historical facts, im discusing about playability of game, and a buff penetration like main post shows is a complete unbalance.

Edited by Despe
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4 hours ago, admin said:

which part and min?

part one starting at around 31mins. But they scaled it down - question is it linear and how exactly it got scaled down only reference is that the wooden dummy is 20cm thick and represent a typical framing of that time

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Posted (edited)

This is plot of on the left, a single 32lb gun, and a single 4lb gun with velocity vs range. Both set arbitrarily to 1600fps.
A second curve for the 32lb gun represents either double shot, or as listed carronade. (Set to be a range offset of 1000m, representing a V0 of 850 fps in this case.

Note that these appear to all have 'different form' and result from a trajectory with full accommodation for mach drag for the different sized shot (which has a small but dis-regardable difference in this 2:1 scale  change of form (it has a higher impact on the next halving of size, to give an 0.5lb shot, with a reduced performance).

When the carronade velocity profile is shifted to the right by the difference in range at which the full gun and the carronade share the carronade muzzle velocity, and all shot are 'scaled'  by dividing the range by shot calibre, then the right hand plot is seen. Note that the form of carronade and gun are continuous, and that the 4lb gun is scaled in range in nearly direct proportion to it's shot diameter (e.g. the three plots so adjusted overlap and are nearly identical, despite the large differences in initial velocity, and the large difference in shot size/weight).

The 'shape' of each is approximately the same. The 4lb curve reduces over a range of 50% of that of the 32lb curve, but is otherwise of the same form. The 32lb carronade curve is merely offset by the range at which the long gun falls to the carronade performance.

All of these trajectories are for 1nm, and are all in the 'flat fire' regime where trajectories are reasonably rigid, and limited by air drag rather than by trajectory form and gravity. The Carronade has the steepest angle of projection, and the 4lb gun loses the most velocity over the distance (and has the lowest velocity outside of approximately 1000m)

The size of the shot is 2:1, the 32lb gun penetrates at the same velocity as 2:1, and carries it's velocity losing the same proportion over a distance in ratio 2:1 (i.e. 'penetrates' the air in the same proportion, nearly exactly).

 

ScaledVelocity.thumb.png.50a0ac2f52c4f54d401fb9858a9b0a8b.png

 

Edited. Slight missspeak, the right hand range measure is not 'calibres' but rather metres/calibre in inches. The implication remains the same, just a scaling constant and labelling difference.

Edited by Lieste
Update to correct error in naming of second graph.

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Being a hunter and a sport shooter who reloads and develops my own ammo loads, a lot of gun pen comments missing two important factors when address penetration.

There are too main factors. Kinetic energy of the projectile and the area size of the impact. Im not even touching the ballistic coefficient. We are talking about when your projectile have made it to the target.

On normal conditions (no angles or stable target) its the kinetic energy mass by area.

Kinetic energy calculated from speed and the weight of the projectile. Area of application (in our case) is the size of the cannon ball.

Thus, where 42pd cannon ball would bounce without a dent a small musket bullet would penetrate some portion of armor and stuck in it.

So on top of the initial penetration there is also a factor that tells how a specific projectiles saves the energy. Small projectile might have higher initial pen due to high speed and small size of the projectile, but soon as it makes impact it looses all its energy and stops getting stuck in the armor. Large cannon ball if pen will carry the energy further through the armor due to its weight

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Posted (edited)
On 7/31/2020 at 9:13 PM, Jan van Santen said:

Actually even a 6 pounder didnt penetrate a lo/wo hull, even below 100 m. The docu used a 6 pdr shot against a model of the "Constitution" hull. 

wo would be penetrated, lo/wo would not.

The experiment was done for "Master and Commander- The true story" docu. I cant access the actual docu atm, but the experiment can also be seen here, around 7:50

 

Its alot of different elements thats plays in, here is a really good read on the topic, with credible source at the end. 

In general im really interested to see if it actually will matter, considering the insane amount of hull damage the carronades do i still believe there will be a meta around carronades ships and angling until you're close enough

https://www.quora.com/Why-did-USS-Constitution-bounce-cannon-balls-off-of-her-hull-Was-she-really-so-superior

Edited by You

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I wish we could access this documentary in English - anyone able to supply the link? Actually I question the experiment....the target wall is propped to upright using 2 flimsy braces, which would give more easily that of the target were part of a larger structure. Also, it is hilarious seeing them stuff grass down a muzzle for wadding. Makes one wonder how careful their other methods were...

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1 hour ago, Preechur Blackheart said:

I wish we could access this documentary in English - anyone able to supply the link? Actually I question the experiment....the target wall is propped to upright using 2 flimsy braces, which would give more easily that of the target were part of a larger structure. Also, it is hilarious seeing them stuff grass down a muzzle for wadding. Makes one wonder how careful their other methods were...

I am a native German speaker, in the documentary they say that a British weapons expert has built the experiment to scale and the grass/straw is used to compress the load, as it was done in the past. Also the cannonball is moving much too fast to let the wood disperse some energy by moving. So i think the experiment is quite relevant 

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@admin when are this changes going to be applied? is it going to be deployed with the karma system? or are they 2 separate patches? new ETA?

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8 minutes ago, DonH said:

@admin when are this changes going to be applied? is it going to be deployed with the karma system? or are they 2 separate patches? new ETA?

They will first put gunnery and wind changes on testbed (soon), while Karma is posponed

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so...seen the doc ..................... live oak /   white oak/  it is then...

 

 

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