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Subject: 140mm 120mm gun and their muzzle energy
Adamantine    6/15/2004 2:13:57 PM
Some sources indicate that the L55 120mm Rheinmetall long barrel gun has a muzzle energy of 13J to 13.5 MJ. Which is more accurate? L44 Reheinmetall gun is quoted to have a muzzle energy of 11 Mj and 11.5 MJ and other source. What about the 52 calibre M256 gun use by ABRAM ? A Rheinmetall source indicate that a 140mm gun would have a muzzle energy of 25 MJ while most sources state a lower figure of about 17 MJ. From direct extrapolation from the 120mm design, I found that figure is between 17.5 MJ to 21 MJ. Any comments? Lockheed Martin has won the contract for CKEM. It will weigh less than the 174 pound LOSAT but probably heavier than the ideal 50 pound that the US army wish to have. Its probable weigh is 90 plus pound and its speed is Mach 6.5. What is the muzzle energy?
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Horsesoldier    RE:140mm 120mm gun and their muzzle energy   6/15/2004 4:12:00 PM
>>L44 Reheinmetall gun is quoted to have a muzzle energy of 11 Mj and 11.5 MJ and other source. What about the 52 calibre M256 gun use by ABRAM ?<< M256 is the L/44 Rheinmetall gun.
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hybrid    RE:140mm 120mm gun and their muzzle energy   6/15/2004 11:29:35 PM
CKEM is a missile, not a round, hence no muzzle energy, but for comparisons sake LOSAT had an impact energy release of 35-40 MJ while CKEM is hoping to get around 15 MJ. Mass is the key difference here.
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Adamantine    RE:140mm 120mm gun and their muzzle energy   6/16/2004 2:17:58 PM
Found a source that indicate that losat is 60MJ and L44 120 mm is 12 MJ. It seem to me that the 12MJ attributed to L44 120mm seems to be too high. An electrothermal version of M256 (license copy of L44 Rheinmetall) is suppose to register 14MJ. The difference between ETC gun and conventional gu should be at least 25%. Seems like those source that indicate a 11 MJ to 11.5 MJ figure for L44 seems more credible. If there is accurate data on the exact muzzle velocity of M829E3 round and the exact weight of the round before the sabot is discarded, we should be able to derive an accurate figure using 1/2mvsquare formula
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Adamantine    RE:140mm 120mm gun and their muzzle energy   6/16/2004 2:47:08 PM
Nobody know the exact weigt of the final production version of the Lockheed Martin CKEM. But lets assume the lower end of the estimate which is about 88 pound. Peak speed is about Mach 6.5. Lets assume impact speed of Mach 4.5 after travelling to near its maximum operational range. Kinetic energy before impact should be about 33.8 MJ If impact of target occure at peak velocity, the impact energy is 71.8 MJ !!! No tank on earth could remotely withstand a direct heat, frontal armour or not. Only way is to use active defense like a explosive formed projectile from active defense system. However, ven then, the kinetic energy of a CKEM is so awesome that even if it fail to penetrate the intended target due to a change of course due to an impact of an active armour (eg explosively formed projectile), the ckem could act like a HESH round even if SLAM onto the target without having the penetrator pointing at the target tangently. even if the whole missile SLAM onto the target with its body instead of its sharp edge, it would be interesting to see how the 33 to 60MJ of energy would do to a turrent or fronal armour of a tank. I guess most of the tank crew may get slip disc, heart damage due to severe vibration, concursion etc. Optics will crack, turrent may jam. Thats enough to disable a tank. Most army that operate Russian style tank follow the Russian doctrine of abandoning most disable tank during battle. Tank would only be repair is the damage is light (eg track blown off). This is due to severe shortage of spare parts and porrly train conscript that is not capable of complex repair job. During the cold war, Warsaw pact tank outnumber NATO and non aligned non european country (eg Swutzerland and austria) by 68000 to 31000. About 2.2 to 1. This ratio may be reduce to 2.1 is to 1 because Russia has to reserve at least 3500 tank in ASIA to defend its bother against China (pseudo western ally in cold war) and the volatile southern frontier. However, the western tank is much more well maintain in peace time and will be well supported in war time. Israelis experience in Yom Kippur war indicate that when you are outnumber 3 is to 1 or even 10 is to one, many of your tank (western design) will receive many hit in day. Some of the hit will detroy your tank (western design) but most will just disable your tank or fail to penetrate. The israelis (even though its a conscript army) manage to repair most of the disable tank and send a very high percentage of them back to war within a short period. NATO has the policy to repair tank in war. If West Germany could hold the Warsaw pact invasion (after full mobilisation) for a week or so before being partially or completely overun by the hordes of 60000 plus thousand tanks, NATO will have a good chance of rolling the hypothetical invasion back because numerous Warsaw pact tank would break down and fall into disrepair. More fortification can be done in France and western part of West germany to further ENHANCE the so call DEFENDER advantage. Couple with superior training, logistic and tank gunnery, once the ratio of attacking tank versus defending tank falls to 1.5 is to 1 after a few days fighting, the NATO tank will suddenly be a situation where it is much more easy to be on the slaughteing side as superior gunnery plus fortification and battlefield intelligence will enable NATO tank to slaughter an attacking force that has only a 1.5 to 1 numerical advantage. A few outslaught will CAUSE mutiny in those less reliable eastern europr allies and the category three Russian reserve division. Mass exodus may result. Soon The attacking force will be attcking with 1 to 1 ratio against defender. There is no contest. Just a thought ... ... ... what you guys think?
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Adamantine    RE:140mm 120mm gun and their muzzle energy   6/16/2004 2:51:28 PM
sorry I have writen too fast in the previous post and there is an embarrassing amount of grammer, sentence structure and spelling mistake. My apology.
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