Gun measurements request

Ranger-75 · Post by **Ranger-75** » Mon Sep 30, 2002 6:17 am

Jeremy,

Please, please, please do not use metric measurements for guns 4 inch and over in the newest version, it will confuse the hell out of folks.

Also, if there was only 1 gun of a size (like the Yamato class 18", then there's no need for "18" type 97" or whatever it is, because there was never a type 96, type 98 or any other type of that gun. For the numerous 5", 6", & 8" guns, this is obviously necessary, but let's keep that table as simplified as possible.

Thanks in advance.

pasternakski · Post by **pasternakski** » Mon Sep 30, 2002 6:30 am

Thank you, Ranger-75, thank you thank you thank you.

If your suggestion is followed, it will save a lot of us ignorant, ugly Americans from having to buy (or create) a conversion chart to tape up next to the computer screen.

Could you imagine Kirk Douglas in "In Harm's Way" looking down on the Yamato and talking in amazement at the size of the main guns by saying, "They look like - umm, let's see, here, 18.1 inches times point thirty-five is - ah - approximately, ummm..."

Jeremy Pritchard · Post by **Jeremy Pritchard** » Mon Sep 30, 2002 7:28 am

You know, it really isn't that hard.

80mm = 3"
100mm = 3.9"
120mm = 4.7"
127mm = 5"
140mm = 5.5"
200mm = 8"
350mm = 14"
410mm = 16.1"
460mm = 18.1"

They are actually more 'even' numbers then the Imperial system. It does not really take much to understand the conversion, as it is in very similar incraments, and is probably more logical. Ever wonder why the Japanese and French had such odd sized guns, like 3.9"? This was because they perfered round numbers, like 100mm.

The main reason that the 460m (18.1") guns retain their type marking is primarily for continuity. All weapons had a Mark or Type or year, and if it will be added for some, why not all? It is just like why I had Japanese names for aircraft (with blank for those without nicknames) instead of using a mix of Japanese and US nicknames.

I understand your reluctance for the new measurements, but it really is not hard to know two systems of measurement. I will create a 'backwards measurement friendly' version.

"My car gets 50 rods to the hog's head, and that's the way I likes it!"

pasternakski · Post by **pasternakski** » Mon Sep 30, 2002 7:54 am

Thank you, too, Jeremy. Lead us along gently, now. This is a big, brave new world for me...

Nomad · Post by **Nomad** » Mon Sep 30, 2002 7:54 am

I don't have a problem with the metric measurements, but I would with a car that gets .0025 mile per gal.!!

Capt. Harlock · Post by **Capt. Harlock** » Mon Sep 30, 2002 11:16 pm

Actually, the closest metric bore to 3-inch is 76mm, which explains why there were a number of tank guns made in that size. 80mm works out to 3.15 inches.

Denniss · Post by **Denniss** » Tue Oct 01, 2002 1:38 am

If I rember correct the Yamato had 45,7cm main guns = 457mm = nearly 18.1"
Usual gun size was 20,3cm = 203mm =8"
same with ~35.5cm = ~355mm = 14"
or 38.1cm = 381mm = 15"
or 105mm = 3,9"
or 150mm = 5,9"
or 128mm = 5"
Americans had 40,3cm or 40.6cm guns
=16"

Sardaukar · Post by **Sardaukar** » Tue Oct 01, 2002 3:19 pm

Russians also went into this inch thing...their favourite artillery caliber is 152 mm aka 6 ". I don't have trouble with aproxximate conversions, albeit exact numbers can be difficult. Try to multiply 5.25 inches by 2.54 cm in your head

. And in gunnery, those figures can differ, depending how the measurement was done.

Cheers,

M.S.

showboat1 · Post by **showboat1** » Tue Oct 01, 2002 9:08 pm

My Gawd! Metric system in a game dealing with Americans! Its lunacy! A declaration of war will be on its way to Congress soon. If this thing switches to metric then I'm in big trouble. It will take me FOREVER to go into my editor and them ALL back to inches. THe wasted time could affect my psychosis in a negative manner. PLEASE, NO METRIC!

Denniss · Post by **Denniss** » Tue Oct 01, 2002 11:00 pm

Jeremy wants to use metric system only for the japanese as they historically used it .

And how difficult it is to swicht from inches to metric system - ask NASA !

They lost something onto the Mars

due to some failures in converting metric system values into inches or vice versa

Ranger-75 · Post by **Ranger-75** » Wed Oct 02, 2002 5:09 am

I know how to convert, and everything,
25.4mm or 2.54cm =1"
76.2mm = 3", etc., etc.

But it is a pain in the a$$ to figure out the many variations on the 4 - 8 inch range of guns. so I'd much rather not have to.

Of course the British had the screwiest system of all:

Does anyone know the bore of the 2 pounder, 6 pounder, 17 pounder and 25 pounder??

(of course i know, just testing you all (there were 2 different 17 pounders made too))

Chmee · Post by **Chmee** » Wed Oct 02, 2002 3:21 pm

He he, accept my 2 cents as well.
First of all in spite of what Ranger-75 says, British system was the most reasonable. That's because it is a shell's energy that we should be most interested in, not its diameter. Much of course depends on the shell's usage.
1. If it is a kinetic armour piercing shell (AP) then we need its weigth _and_ speed to calculate its energy and thus compare with other shells. German Panther's 76 mm gun was a more fearsome tank killer then the early Tiger's 88.
2. If it is a HEAT round, then the diameter is crucial. The bigger, the better.
3. In the case of a simple HE bomb the weight shuld suffice since the proportions of explosives to steel cover are more or less the same all the time. Unless you fit a nuke into a shell that is.

Of course Brits could use kilograms instead of pounds

.
Cheers; Chmee

Denniss · Post by **Denniss** » Wed Oct 02, 2002 4:03 pm

Panther had a 75mm gun (caliber lenght 70) not 76mm - the russians had around 76mm .
The Tiger I 88mmL56 gun was not far away from Panther .
Both could kill T34/Sherman at over 1000m

Newer version of guns with same size usually have better weapon data so they have to be implemented .

Skyros · Post by **Skyros** » Fri Oct 04, 2002 3:24 am

I always thought that the use of metric had something to do with caliber envy.

Ranger-75 · Post by **Ranger-75** » Fri Oct 04, 2002 7:17 am

The German L/56, L/70, etc was a common European method of defining the Gun. the 88mm L56 gun meant that the barrel diameter was 88mm and the barrel length (from breech end to muzzle) was 56 times the dialeter, or 56 * 88mm (and I'm not going to do the math).

The Panther's 75mm was so effective bacause it was an L/70 gun, Length was 70 * barrel diameter, giving it a very high muzzle velocity. This combined with good german ammunition and excellent fire control equalled a lot of shot up T-34's , KVs and JS-IIs as well as a sh!tload of Shermans, Cromwells, Churchils, etc. The Tiger II's 88mm was an L71, making it even more powerful than the Panther's 75mm/ L70.

The 17 pounder on the Sherman Firefly (a 76.2mm Gun) also had a very long barrel making it equal in power to the Panther's 75mm. The US 76mm gun M3, while a lot better then the 75mm gun, was not as good as the Panther or Firefly's gun

Ranger-75 · Post by **Ranger-75** » Fri Oct 04, 2002 7:19 am

I still don't want to see metric guns over 4" in the new version

IntellWeenie · Post by **IntellWeenie** » Fri Oct 04, 2002 9:10 pm

Originally posted by Ranger-75 The German L/56, L/70, etc was a common European method of defining the Gun. the 88mm L56 gun meant that the barrel diameter was 88mm and the barrel length (from breech end to muzzle) was 56 times the dialeter, or 56 * 88mm (and I'm not going to do the math).

This is already in the game; the 5/38 Mk-12 is a 5" gun with a barrel length of 38 calibre. Generally speaking, longer calibre guns produce higher velocity which translates into greater range and striking power. While velocity is very important for tank guns, it's not as important for naval guns as being able to out-range your opponent. Another way to increase range is to use a larger diameter bore (more propellant, heavier projectile which retains energy better).

Plunging fire (not modeled in Pacwar to my kmowledge) is also extremely import to naval surface warfare as deck armor is normally much thinner than side armor. Higher velocities flatten the arc of the projectile making it harder to hit your target from above (rather than the side), especially at closer ranges. That's why you don't see many naval guns above 45-50 calibre, but the gun bores kept getting bigger.

My vote for how the guns are listed:

Use whatever designation the owning country used. There's already a mix of metric and standard anyway....

CynicAl · Post by **CynicAl** » Fri Oct 04, 2002 11:19 pm

Originally posted by IntellWeenie
My vote for how the guns are listed:

Use whatever designation the owning country used. There's already a mix of metric and standard anyway....

The official Japanese designation for the Yamato's 46cm guns was "Type 94 40cm" - a deliberate piece of misinformation planted to deceive any spies who got hold of the plans for these monsters before the war. The designation never was changed, though, so "40cm" guns they remained - officially.

Apart from this one specific instance, though, I tend to agree. Not only does it add to the historical flavor, it also makes it easier to keep track of which guns are whose if you're playing with them in an editor.

Ranger-75 · Post by **Ranger-75** » Wed Oct 09, 2002 7:37 am

Originally posted by IntellWeenie

This is already in the game; the 5/38 Mk-12 is a 5" gun with a barrel length of 38 calibre. Generally speaking, longer calibre guns produce higher velocity which translates into greater range and striking power. While velocity is very important for tank guns, it's not as important for naval guns as being able to out-range your opponent. Another way to increase range is to use a larger diameter bore (more propellant, heavier projectile which retains energy better).

Plunging fire (not modeled in Pacwar to my kmowledge) is also extremely import to naval surface warfare as deck armor is normally much thinner than side armor. Higher velocities flatten the arc of the projectile making it harder to hit your target from above (rather than the side), especially at closer ranges. That's why you don't see many naval guns above 45-50 calibre, but the gun bores kept getting bigger.

My vote for how the guns are listed:

Use whatever designation the owning country used. There's already a mix of metric and standard anyway....

If you study your elementary physics, you will find that velocity, muzzle velocity in particular, has a direct bearing on range at ANY elevation. This is because friction and gravity work on reducing this initial velocity. The higher the initial (muzzle) velocity, the longer the range.

That's why the US 16/50 was so very close in "absolute range" to the Japanese 18/45 - it had a higher initial muzzle velocity. Actual effective range was more a function of fire control than anything else, and here the USN simply outclassed the IJN.

Philodraco · Post by **Philodraco** » Sat Mar 01, 2003 4:22 pm

Actually, after the Takao class, the main armament of Japanses CAs, had been changed by really 8"(20.3cm), up to Myoko class it was only 20cm, although Japanses called all of them 20cm naval gun.

Gun measurements request

Gun measurements request

Shell measurement units