請神教,dalao指點

SIlvaticWave

今天跟網上老外討論WW2 15"砲穿深&性能一事
他說Bismarck C/34型火炮性能說成"Gun penetrations are only part of the equation. Many other factors have to be considered when deciding when a gun was very good or not - and penetration is just one of many factors.
Italian guns: had too big dispersion at long range due to low quality propellant. They also suffered from low quality shells and unreliable fuzes. Meanwhile Bismarck gun tests proved the guns as pinpoint accurate at all ranges and the shell proved deadly when hitting. The italian gun also had a very high bore degradation (110 to 130 rounds tops before needing a reboring, which is neither cheap nor easy to accomplish. Bismarck's gun lasted for a rated 210 shots). Littorio had 25% less shells per gun than bismarck too. The italian gun had a rate of fire of 1.3 rounds per minute in the best circunstances. Bismarck achieved 3 rounds per minute per gun under tests by the Artillery Test command, though granted this was under ideal circunstances too. It's widely granted that Bismarck was able to fire 2 rounds per minute in action from her main guns without too much of a hassle, though. One of the few big guns able to do so. Certainly the italians weren't even close to that rate of fire.French guns: Your figures are for the 890kg shell fired at 2750fps. By 1942 there had been several issues with the propellant bags causing overpressurization in the gun's bore, which risked a predetonation. Propellant charge per shot was reduced as a result, and at the new 2580fps didn't produce the penetrations you mentioned (though they still were generally superior to those of the 38/C34 guns). But the main problem with those guns were the reload mechanisms,  as the hoist design in Richelieu's turrets was downright awful. By early 1940 those guns were reported to be able to fire 1.3 projectiles per minute but that was optimistic to the extreme, to the point that in June 1940 Richelieu was only capable to fire her main guns in an opening salvo...to then fall silent for 15 minutes because that's the time a charge took to go up from the propellant storage to the gun breech. You can find the exact quote about that in the gun description in navweaps.org. Later on (in dakar) the guns were reportedly fired once each couple minutes so probably some of the problems were sorted out, but still that's a 0.5 round per minute true capability. The whole reload mechanism had to be rebuilt postwar, it was so poor.Obviously penetration is nice but if you can barely fire your guns a couple times each five minute, while the enemy is sending two salvoes per minute on your direction, that penetration is worth nothing.British guns: I don't know where you got your penetration values for this gun, but they're wrong. The WWII 879kg shell at 9.1km had a penetration value of 16.5 inches on vertical protection. The german 38cm guns on bismarck were capable of 20.1 inches of penetration at 10km. But at least the Mark I, unlike the ones you mentioned which had their good deal of faults, was indeed a great gun, one of the greatest in history. Fast firing, reliable, acurate and hard hitting. Bismarck's guns were better against vertical protection, but the british Mk.1 15'' guns were much better at deck penetrating plunging fire. At any rate Bismarck's 15'' guns were pretty fearsome - quite more so than the french "I can't reload, sir" guns, or the italian "too heavy of a shell, too fast of a velocity" short-lived barrel (not to mention, innacurate) 15'' guns"意即意呆高穿沒卵用,因為打不準,炮用不久要换
法砲裝塡不好,又因火藥問題不能用全裝藥
德意志機關炮又凖
So bad your resulting data doesn't correspond nor adjust to the historically proven data present in Garzke&Dulin books. Which incidentally also come from historical sources. How fun it is that those sources say something for them yet they seem to say something different to you guys. ;)From a physical perspective and remembering my old days in college learning ballistics and laws of movement, for me it doesn't make any sense that a shell fired at 70m/s less of MV while only being 80kg heavier than another one shows a higher penetration ability. Kinetic energy squares the velocity, not the mass, hence unless at extremely long ranges (where vertical penetration is meaningless anyway), the lighter shell fired at higher velocity will penetrate more because it'll have more impacting energy. Even accepting hypotentical aerodinamic advantages of one shell over the other one (which don't exist in this particular case, the british 6cr shell wasn't specially aerodynamic nor had a specially remarkable ballistic performance) there's just no way around it. It's just simple physics at work.I'm sorry, until you guys are recognized as world leading authorities on the matter, as those authors are, I'm taking their penetration tables as reliable sources...and not yours. Specially when your conclussions run opposite to what physical laws say is common sense. No offense intended.

又吐嘈我給出神教的15inch Mark 1 6crh 穿深不準確, 下圖,並用 Battleships: Axis and Neutral Battleships in World War II, by William H. Garzke Jr. (Author), Robert O. Dulin Jr. (Author), Thomas G. Webb (Illustrator)來說自己多正確.
旧炮状态（强装药）

射程	垂直穿深	水平穿深	着速	落角
0yd (0m)	29.30" (744mm)	---	2,575fps (785mps)	0
5,000yd (4,572m)	25.91" (658mm)	0.56" (14mm)	2,312fps (705mps)	2.43
10,000yd (9,144m)	22.50" (572mm)	1.45" (37mm)	2,063fps (629mps)	5.68
15,000yd (13,716m)	19.35" (491mm)	2.40" (61mm)	1,852fps (564mps)	10.02
20,000yd (18,288m)	16.49" (419mm)	3.38" (86mm)	1,683fps (513mps)	15.48
25,000yd (22,860m)	13.95" (354mm)	4.48" (114mm)	1,560fps (475mps)	22.22
30,000yd (27,432m)	11.87" (302mm)	5.80" (147mm)	1,497fps (456mps)	29.93
35,000yd (32,004m)	10.23" (260mm)	7.47" (190mm)	1,496fps (456mps)	38.25

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