Bamse Posted October 5, 2000 Share Posted October 5, 2000 Why have the 105mm gun the same Hc value as the short 75mm gun ? 105 mm wespe, STUG42 75 mm PSW 234/3 The Hummel's(150mm) Hc value is different from the 75 & 105 Björn Elfström Visa pip pip pip vi vill se era pip pip Markolio Link to comment Share on other sites More sharing options...
Bamse Posted October 5, 2000 Author Share Posted October 5, 2000 I would relay like to know, so i'm sending this baby to the top ! Link to comment Share on other sites More sharing options...
Tanaka Posted October 5, 2000 Share Posted October 5, 2000 Hi, Well spoted... I´m curious too João Link to comment Share on other sites More sharing options...
Bamse Posted October 5, 2000 Author Share Posted October 5, 2000 BTS or anybody that have a clue. Please respond ! Link to comment Share on other sites More sharing options...
Tanaka Posted October 6, 2000 Share Posted October 6, 2000 Bump... Link to comment Share on other sites More sharing options...
Kurtz Posted October 6, 2000 Share Posted October 6, 2000 I checked Chamberlain's "the Encyclopedia of German tanks of World War Two" and the penetration of both the 7.5 cm Gr39 H1/C and the 10.5 cm Gr39 H1/C is listed as 100mm @ 30 degrees from vertical. In the game both weapons have a listed penetration of 100mm @ 0 degrees and 86mm @ 30 degrees. Differences in the design of the warhead could be the reason why the penetration of the 10.5 cm isn't higher. ------------------ Spending extravagant amounts of money for marginal improvements is only acceptable in the fields of racehorses and fancy women. -Lord Kelvin Link to comment Share on other sites More sharing options...
Maj. Bosco Posted October 6, 2000 Share Posted October 6, 2000 Check the velocities? The 105's usually have a much lower muzzle velocity. Link to comment Share on other sites More sharing options...
Kurtz Posted October 6, 2000 Share Posted October 6, 2000 The MV of the 10.5 cm is 495 m/s and the 7.5 cm has a MV of 450 m/s. But since both guns fire a hollow charge, MV doesn't matter much. ------------------ Spending extravagant amounts of money for marginal improvements is only acceptable in the fields of racehorses and fancy women. -Lord Kelvin Link to comment Share on other sites More sharing options...
Tanaka Posted October 6, 2000 Share Posted October 6, 2000 C type ammo GERMAN PSW 251/9 HT-----> 75 L/24 vel 450 m/s penet.(100/86/50) differ. 0% (L)+16.6% (V)+10.2% StugH42---------->105 L/28 vel 496 m/s penet.(100/86/50) US M8 Howitzer------> 75 L/? vel 381 m/s penet.( 89/77/44) differ. 14.x % (L)? +24.1% M7 Priest-------->105 L/? vel 473 m/s penet.(102/88/51) So... We can see that, for the Germans the 10.2% increase of velocity and 16.6% increase of the L doesn't produce any alteration on the penetration factor. As for the Americans we can see that a 24.1% increase of velocity (more 13.9% increase then the Germans) produce a 14.x % increase on the penetration factor. In order to compleat the reasoning I need the L measure on the American guns... Thanks, João Link to comment Share on other sites More sharing options...
Jeff Heidman Posted October 6, 2000 Share Posted October 6, 2000 This is pure specualtion on my part, but it seems possible that both rounds actually had the same warhead on them. Perhaps the Germans did not go to the trouble of designing two seperate HEAT warheads, but jsut used the same warhead on top of different shells? Jeff Heidman Link to comment Share on other sites More sharing options...
Maj. Bosco Posted October 6, 2000 Share Posted October 6, 2000 HEAT and hollow charges aren't the same. I don't know if it's possible to put the same hollow charge as is in a 7.5cm gun into a 10.5cm gun with some filler and have it still work... Link to comment Share on other sites More sharing options...
Kurtz Posted October 6, 2000 Share Posted October 6, 2000 Tanaka, the velocity of a "C" round doesn't influence it's penetration. The penetration is the same regardless distance and velocity. The major factors influencing the penetration is the diameter of the hollow charge and its shape. ------------------ Spending extravagant amounts of money for marginal improvements is only acceptable in the fields of racehorses and fancy women. -Lord Kelvin Link to comment Share on other sites More sharing options...
RMC Posted October 6, 2000 Share Posted October 6, 2000 Hollow charge = HEAT. Interesting idea that the Germans may have used the same warhead on both rounds. The 10.5cm would have had more potential penetration if the HC was built to take advantage of the larger size. CM uses the Encyclopedia of German Tanks as a major source. If it is in error then CM is also in error. In any case the penetration figures are the smae only for the last version of the HEAT round. The earlier version had lower penetration in the 7.5cm than in the 10.5cm. Link to comment Share on other sites More sharing options...
Tanaka Posted October 7, 2000 Share Posted October 7, 2000 "...the velocity of a "C" round doesn't influence it's penetration...major factors influencing the penetration is the diameter of the hollow charge ..." So this kindof narrows it down, a 75mm L24 and a 105 L28 "c" rounds should have diferent penetration values... One question still remains, did the Germans used the same warhead on both rounds ? "Differences in the design of the warhead could be the reason why the penetration of the 10.5 cm isn't higher." or the other way arround. I don´t buy this, is to much, look at the diference between the American 75mm and 105mm (+- 14%) João Link to comment Share on other sites More sharing options...
Bamse Posted October 7, 2000 Author Share Posted October 7, 2000 Bump... Link to comment Share on other sites More sharing options...
Colin Posted October 7, 2000 Share Posted October 7, 2000 bumpity-bump-bump Link to comment Share on other sites More sharing options...
Paul Lakowski Posted October 7, 2000 Share Posted October 7, 2000 HEAT penetration is determined by warhead diameter, liner material , cone angle, and warhead standoff. All these factors can dramatically change any warhead penetration. Link to comment Share on other sites More sharing options...
Guest Big Time Software Posted October 7, 2000 Share Posted October 7, 2000 Boy, lots of bumping and I still only just found this message I have forwarded this off to Charles as he is the only one that can really comment on it since he put in the data. However, he is away for the holiday weekend (at least in the NE US) and won't respond for a while. But if it is in error it will be fixed. Thanks, Steve Link to comment Share on other sites More sharing options...
Paul Lakowski Posted October 8, 2000 Share Posted October 8, 2000 <font color=black> OK heres some info for you all to consider before passing any judgement.In the "Journal of Battlefield Technology" a article was published on HEAT developement and standoff penetration chart was published for Steel,Copper and Aluminum cone shaped liners.....here are provisional figures taken from the chart. <PRE> <font color=blue> Standoff in cone diameters Liner 1.0 2.0 3.0 4.0 5.0 6.0 Aluminum | 1.0 1.5 2.0 2.4 2.5 2.5 Steel | 2.8 3.1 3.5 3.5 3.2 2.8 Steel | 3.0 3.5 3.5 3.1 2.6 2.1 Copper | 3.1 4.1 4.8 5.0 4.3 3.8 Copper | 4.2 4.4 4.2 3.8 3.4 2.8 result is the penetration in cone diameters </PRE> <font color=black> The difference between the two copper types appears to be the difference between precision in the manufacture with the last version representing 50-60s technology. [This message has been edited by Paul Lakowski (edited 10-07-2000).] Link to comment Share on other sites More sharing options...
Bamse Posted October 26, 2000 Author Share Posted October 26, 2000 Bump..... Link to comment Share on other sites More sharing options...
Simon Fox Posted October 26, 2000 Share Posted October 26, 2000 <BLOCKQUOTE>quote:</font><HR>HEAT penetration is determined by warhead diameter, liner material , cone angle, and warhead standoff. All these factors can dramatically change any warhead penetration.<HR></BLOCKQUOTE>and IIRC angle of incidence does have a significant effect especially with WW2 era HEAT rounds. Link to comment Share on other sites More sharing options...
Olle Petersson Posted October 26, 2000 Share Posted October 26, 2000 More factors to consider: As Simon put out the angle does matter; When you read HEAT you think "cone with steep walls". Hollow charge wasn't originally conical, but merely a HE with a part-sferical inprint in the front, and thus less effective (per diameter). The penetration of full-blooded HEAT warheads, as function of diameter, does vary with the factors mentioned earlier. But it's also a function of: - Explosive material used. - Spin, any axis, decrease penetration. - Symmetry, the more perfect the better; -- Explosive, homogenious material and symmetric shape down to molecular level. -- Ignition, absolutely symmetric. -- Overall shape, down to molecular/atomic level. In WW2 shaped charges were a new invention, and penetration averaged at about 2 calibres (for HEAT, less for hollow charge) with huge differences between individual warheads in the same batch, due to limitations in production accuracy. Modern (80ies) laboratory tests have provided more than 8 calibres penetration from a HEAT warhead. Modern HEAT rounds typically have 5 calibres penetration. Cheers Olle [This message has been edited by Olle Petersson (edited 10-26-2000).] Link to comment Share on other sites More sharing options...
Guest wwb_99 Posted October 26, 2000 Share Posted October 26, 2000 But here is another discrepency. I noticed last night that a 150mm infantry gun has a penetration value of 150 at 100m. At the same time, a German 150mm howitzer had a penetration of 100. Any comments? WWB Link to comment Share on other sites More sharing options...
Bamse Posted October 27, 2000 Author Share Posted October 27, 2000 <BLOCKQUOTE>quote:</font><HR>Originally posted by wwb_99: But here is another discrepency. I noticed last night that a 150mm infantry gun has a penetration value of 150 at 100m. At the same time, a German 150mm howitzer had a penetration of 100. Any comments?WWB <HR></BLOCKQUOTE> Something is very wrong here(or in great need of explanation. It's a little disturbing that a hamstertread gets more attention than a possible major bug ! Link to comment Share on other sites More sharing options...
Geier Posted October 27, 2000 Share Posted October 27, 2000 <BLOCKQUOTE>quote:</font><HR>Originally posted by Bamse: It's a little disturbing that a hamstertread gets more attention than a possible major bug !<HR></BLOCKQUOTE> I don't get that argument. If any of the participants of the Cesspool could have answered your question they would have. BTS does not, EVER, post to the Cesspool, so no time is taken off their hands by its presence. You have a response from BTS where they said "We'll check this out and get back to you". What more do you want? ------------------ Johan "The succesful execution of a well devised plan often looks like luck to saps." Dashiell Hammett Link to comment Share on other sites More sharing options...
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