kipanderson

Tom w, hi, Yes, it could be that Charles was assuming that German armour was of higher quality than Allied armour. However CM has already got that angle covered. If you select a Panther in CM and then hit “enter”, thereby calling up the Panther’s unit details, you will see an armour quality number of 85% above the armour details. For the Tiger 1 CM has no armour quality rating thereby assuming that the Tiger 1 had 100% armour quality by WW2 standards. The Panther was known for its somewhat poor armour quality and the Tiger 1 for its high quality of armour, see the various Jentz books. So if you just take the Panther and the Tiger 1 as examples then CM have done a good job of covering the armour quality angle. Andrew Hedges, hi, I agree that the “pointer” rounds were optimised for penetration of vertical plate. In all of the above I am assuming the use of APCBC rounds that were optimised for use against angled plate and, as you say, were almost flat under their thin ballistic caps. I am assuming the use of APCBC rounds because these were by far the most common during the second half of the war. BruceR, hi, Yes it may be that some of Charles figures for the German guns are a little generous. However, on the whole, I feel that Charles has got the German figures about right. The figure Charles uses for the 75L48 gun is 108mm at 100m against 30 degree plate. The two figures you normally see the Germans use for this gun are 99mm and 106 mm. I would have gone for a figure of 103mm, i.e. half way between the two. It must be remembered that Charles is also using an armour penetration formula and no two formulas will come up with the exact same figures. Given that, I do not have a problem with Charles penetration figures for the German guns. I feel they are correct and are consistent with one another. The problem is that “given” the figures Charles uses for the German guns his figures for a number of Allied guns are a bit off target, in my view. All the best, Kip.

Hi, My vote would be against WW1. My reason is that compared to WW2 it is tactically uninteresting, in my view. WW2 and modern mechanized warfare interest me most. When it comes to other wars I feel Napoleonic warfare was more interesting than ACW. Of the wars that have actually happened, ie. not modern OPFOR warfare, WW2 and the Napoleonic wars deliver the greatest tactical challenges. Also during the second half of both wars all the major players were very good at what they did, given the limitations of the technology they had available. All the best, Kip.

hi, my vote would go for 40-50 turns. In my view at this scale there would "not" be time pressure on commanders, not down to 20 or 40 minutes. Taking a village in 2-3 hours would be fast, even in a crisis, according to my reading of military history as battles actually happened. Of course sometimes villages would fall in 10-20 minutes but normally 2-3 hours would be a job well done even in a time pressured operation. Also battles seem to have a natural rhythm of 40-50 turns. All the best, Kip.

Hi, About three weeks ago I made the above post regarding the fact that , in my view, some of the armour penetration figures in CM are inaccurate. If we take a quick look at the data for the German L70 Panther gun and the British 17pdr common sense would indicate they had a similar penetration figure. If we start with muzzle velocity, L70 gun 925 meters per second, 17pdr 884 meters per second. When it comes to projectile mass, L70 6.80 kg, 17pdr 7.71 kg. They were of course of similar diameter, L70 75mm and 17pdr 76.2mm. Because armour penetration is more sensitive to increases in velocity than increases in mass, for a similar diameter, the 17pdr has only a fractionally greater penetration than the L70 gun, by about .5 of a millimetre. Charles’ figures for penetration at 100m against a plate at 30 degrees are L70 gun 139mm, 17pdr 118mm. Clearly there is a case to be answered. I am a huge fan of all things CM and would not like to drag Charles away from his TCP/IP coding as I greatly look forward to sending my friends Panzers up in smoke live over the net. However in the case of the 6pdr, the 17pdr, the US 76gun and the US 57mm AT gun I do believe CM currently has the wrong penetration figures, given the figures Charles uses for the German guns in CM. It would be a shame if Charles did not get round to checking his calculations although I know he already does huge hours. All the best, Kip.

Hi, I would just like to add my thanks to Bill for all his work. I am one of those lazy people that enjoys others scenarios but never bothers to produce anything myself that is polished enough to go public with. Thanks again, Kip.

Hi, I have been wondering about the same thing. I have often wanted to expand down or left but thought it impossible. If it is possible that is great news. Off to give it a test run. All the best, Kip.

Hi, this has been an interesting thread and I am quite happy to sit back and just follow the arguement. If it came to taking sides then I would go with Steve and John Waters (PzKpfw1). The true test of real world battlefield conditions is the number or rounds fired per kill. When you consider that "kill claims" are likely to be a huge exagaration on reality, in my view, and anyway look at ammunition expenditure, the difference between fire on ranges and battle fields is likely to be very great. Anyway the piont of my reply is to do with the fact that it has been claimed that "spotting" tank and anti-tank fire is too easy in CM. I disagree with this. Over the years I ahve only seen only a few clips of film of WW2 tanks firing, but what is clear is the huge blast and flash of fire and smioke that resulted. If someone was observing a given area it would be very difficult to miss in any terrain, even at long distances. All the best, Kip. PS. The reason why I feel "kill claims" are likely to have been hugely exagarated, on all sides, is my view of the great "emotional" pressure individuals must have been under to believe they had achieved a kill.This is just my view, others will differ.

Hi, it depends on the time of year you plan to visit. If you plan to visit in the winter months then the Ardennes has to be the place. I have been there for two private battlefield tours at Christmass time. The atmospher is great, in the half light of winter you can almost hear the panzers rolling over the hills and through the undergrowth. If you are coming to the UK then The Tank Museum at Bovington in Dorset is a must. There may be just one or two other tank museums in the world that are as good but probably not. Duxford, 50 miles north of London, is also top quality. Ever seen a Joseph Stalin 2 tank for real? Duxford is the place to go. All the best, Kip.

Hi, after the Eastern Front my vote would also be for modern warfare. If you assumed all sides could make use of weapon systems that are mature, have been on the export market for a year or two and shown to work as advertised, then it would be a fairly even contest even today. Plus of course it does not have to be the Russians V the US, why not the Germans V the US? I also agree the a 1980 version of CM would have special appeal for many of the reasons given above. With the stunning engine Charles and Steve have developed it would be a shame if we never saw an "Opposing Forces" version. Steve, Charles why not licence out the engine just for a modern version of CM while you continue with your fine work on WW2? All the best, Kip.

Hi, There seems to be a feeling that there should be somewhat tighter modelling of command and control in CM. I am against this. For me, others will differ, it all comes down to what you want CM to be and when engaged in a game what “role” you feel you are playing, i.e. platoon commander? company commander? Whatever. For me CM is about tactics, tactics and more tactics. It is really a simulation of the tactical problems faced in WW2 and given the decisions you make it accurately models the outcome as it is likely to have been in reality. Tactical realism is what I am after and this is what CM delivers in lorry loads. However given the capabilities of today’s computers and the fact that on each side there is just one player, commander, it is not a “perfect” simulation of all aspects of WW2 warfare. There are two particular areas in which it falls short, through no fault of BTS. The two areas are “spotting”, or line of site, and command and control. When it comes to spotting the problem is that as just one person you can see the entire battlefield more clearly than any one person could in reality. This is unavoidable because you have to be able to “see” everything any one of your units can see and you can not then “block out” what one squad can see while taking the decisions a company commander makes. When it comes to command and control the problem is that it is not possible to accurately model the command and control problems of say, a platoon commander and a squad leader at the same time. In the perfect world the squad leader or individual tank commander should be free to command his unit in the light of what that unit can see, within realistic morale rules, panicked troops do not do what they are told. However you also want the command and control problems of the platoon commander to be accurately modelled. This would mean that in certain situations it would take quite a large delay for an individual manoeuvre unit to respond to a command from a platoon HQ. Sadly it is not possible to have both at the same time, realistic modelling of a squad leaders control and freedom of movement and realistic modelling of a platoon commander’s command and control difficulties. If you want to more accurately model command and control it means that there will frequently be situations in which you find you are unable to order a given squad to take some urgent action that is required as a result of something the “squad itself can see” because it is outside the control of the platoon commander. Orders that in real life a squad leader or tank commander would give will be “artificially” delayed due to the fact that the platoon HQ is too far away. In my view this would far out weights the benefits of more realistic modelling of the problems of platoon HQs. In CM you play the role of battalion commander, company commander, platoon commander and, most importantly, squad or tank commander. If you want to model more accurately the command and control problems of HQs you have to sacrifice the “tactical” independence of squads and tanks to take the most realistic actions “within” their own environments. With the “one minute movie” this already happens and the TacAI handles things stunningly realistically, but I would not like to go further down the road of loss of control of the individual manoeuvre units. For me the most important role you play in CM is the squad or tank commander, not the platoon or company commander. At the moment CM makes an attempt to take some account of command and control but not too much. I feel they have got the balance just right. Of course there is an obvious answer to both the spotting problem and the command and control problem that I am sure will come in later games. That is in live internet play have more than one player on each side. If you had three or four players on each side and each could only see what the units they controlled could see plus the players had to communicate with one another using text messages, no doubt some would also use the phone, one would have a far more realistic game. This is my number one wish for CM2, that Charles introduces more than one player per side in live internet play. It would no doubt require big coding changes but my advice, however little that is worth, would be to go for it. All the best, Kip.

Hi, I agree with the others, stunningly good. All the best, Kip.

Slapdragon,hi, good to see you are up and about again. When I start a new thread I try to put all the evidence to support by view up front because I know there are a lot of people that come to this forum who know their subject. If you are going to make a claim that Steve and Charles have got something "not quite correct" you had better have evidence to suport the opinion. Its my respect for what others know about WW2 related subjects that drives me to make an effort if there is something I want to say. Its simply a waste of time to start a pnew thread without getting your fact together. Hope you are soon back to 100% running order. All the best, Kip.

Hi, thanks for the hint, I will take a look at them. Kip.

Hi, I think it sounds great, I would use it and be very grateful for it. Just what is required. Kip.

Hi, when it comes to CM2 my big fear is that Steve and Charles "will" try to model the low quality of Soviet officer training during the first two years of the war. The reason why I believe this "should not be modelled" is that in CM you are the officers. In CM you play the part of the platoon leader, the company commander and the battalion commander. So there is no way of modelling the lower quality of Soviet officers in the first part of the war without introducing artificial restrictions on what "you", as a Soviet officer, can do. The way Squad Leader dealt with this problem was to "fix" the result be artificial lowering the quality of some Soviet maneuver units, the restrictions on the range of Soviet rifle units is a good example of this. I feel this approach is not the way to go. Far better to have Soviet maneuver units accurately represented and just except that the gap in ability between two CM players is not likely to be as great as the average gap between Soviet and German officers was in the first two years of the war. For a feel of how it really was play the AI. It is also worth noting that the latest research to come out of the Russian archives suggests that man for man, unit for unit, the Soviets were just as good soldiers as the Germans, on average, during the second half of the war. Therefor there is no need to even try and "fix" the result regarding the post-Kursk faze of the war. There is no short or quick way to explain why this the case but when I have time I will do a far longer post giving detailed reasons why it is now believed Soviet combat effectiveness was as high as German combat effectiveness, on average, during the second half of the war. All the best, Kip.

hi, you guys do think of everything. My spelling is so bad that in the past I have been rather embarrassed just to blast out a reply or post without the spell check. The bad news is that now that there is a spell check there is no reason why I should not just post away as the feeling takes me! I am afraid there is a downside to everything. All the best, Kip.

Hi, I wish I was off to the Ardennes this weekend, have been there a couple of times and hope to return this December. If its not too late and you do not already have them may I recommend some books for the trip. The series of books is published by Osprey and written by Bruce Quarrie. They are part of the "Order of Battle" series. Ideal for a battle field tour. Like many people I have a lot of books on The Bulge but for tour purposes the books by Bruce Quarrie called The Ardennes Offensive are the best, in my view. All the best, Kip. PS. When at La Gleize do go on and walk the Stoumont battlefield.

Hi, This is an interesting subject and my own view is similar to many others that the reason for greater interest in the Germans is the commonly held belief that they where better soldiers. Interestingly the latest research to come out of the Russian archives suggests that in the second half of the war, say from July 43 to March 45 the Soviets had the highest combat effectiveness of any of the major players, on average. That is man for man, or per 1000 man combat team, the Soviets were better soldiers than the Germans. This is a very big subject and there is no quick way to explain why it is likely that this was the case but I will be doing a long and detailed post soon giving my reasons for this conclusion. Out of respect for those that hold the opposite view, that the Germans were the better soldiers, I feel I should justify my reasoning in detail, which I will do when I have time. Another sign of the greater interest in the Germans is the fact that recently I did a post explaining why I believe Charles has got the wrong penetration figures for some of the most common allied guns in CM. As was pointed out by others there was a far more relaxed response to the idea that the US and British armour penetration figures are understated than there would be to the idea that say the Tiger’s 88 is understated. (I do not mean BTS were relaxed about it, although interestingly Charles has not responded, but the CM community as a whole is less concerned about the Allies than the Germans.) All the best, Kip. PS. The armour penetration post was called “ German armour penetration overstated?” if any one is interested.

Hi, I would also recommend the book. It is a bit "nerdish" but that is the entire point of the book. Also 600 very fine photos. Its expensive but in my view worth the money. Military Miniatures In Review, the most "adult" and best of the 1/35 model publications, claims Panzertaktik is the best yet from the publisher, Ferdorowicz. All the best, Kip.

McAuliffe, hi, I am a huge fan of your scenarios and have emailed you before to congratulate you on your work. I find that your scenarios are very well balanced. Difficult but achievable, which is just how it should be. I should add that I always play the part of the attacker, the AI is more suited to defence, in my view. When doing historical scenarios I feel it is important to stick to strict “historical” accuracy even if it did lead to an imbalance in the game, that is how it was for the guys at the time. If that was the case then it is a simple matter, with the use of the editor, to change the forces but still make use of your wonderful maps. After I have played your scenarios I always make use of the maps for other games anyway. I look forward to lots more scenarios from you, and now operations also. All the best, Kip. PS. At time of writing, 1900 UK time, your site is down.

Hi, my copy of CM took about three weeks, that was to the UK, in fact three weeks plus. All the best, Kip.

Ari, hi, No, you should not automatically assume that the latest armour penetration formula is the best one. It all depends on the data the formula is based on. The study of the type of ammunition most commonly used in WW2, APCBC ammunition, peaked during that period. After the war the world moved on to other types of projectile. For example today there is a lot of study of segmented APFSDS projectiles as these will be the next thing widely used in current tank guns. The Milne-de-Marre formula is likely to have started life around the turn of the last century when there was a lot of study of armour penetration against battle ships. It was then tweaked during WW2 into its current form. I know it works well on WW2 APCBC rounds because I produced something very similar using data giving the strike velocity and the penetration of the projectile from the Panthers’ gun as range increased. I got it in its current form from a textbook written by the staff at the Royal Military College of Science, Shrivenham. Guys that do this sort of thing for a living. Paul’s formula will be great and will do what ever he has designed it to do extremely well. I look forward to seeing it. Thanks for your generous comments on my post. All the best, Kip.

Steve, Given some of the responses people have made to my post I thought I had better start by confirming what I hope you already knew, that is that this is in no way meant as a criticism of CM or of you and Charles. There is no bigger fan of BTS than I am. CM is the only computer game I play, just now and then Steel Beasts and BCT make it too. The reason is that what I am after, and what you deliver in vast quantities, is tactical realism. Everything is of stunningly high quality, including the armour penetration figures. I just thought it would be fun to do my own “consistent basis” calculations and see what came up. And then to follow that by a friendly debate between fellow armour penetration nerds. As I say in my post the fact that there will now never be a 100% correct answer to these questions I feel is rather fun. It has never crossed my mind that there was any pro-German bias in the game. As I say no criticism it implied it is just my two pence worth on the subject. I realise not every one will agree with me and am quite relaxed about it. One reason I make an effort to get things as correct as I am able is my respect for the knowledge of others on this forum including of course all those at BTS. Slapdragon, hi, I thought I would just take the opportunity to thank you for your very generous comments on my post. Its incredibly kind of you to give me such a fine write up, I will have to use you as a reference! John, thanks also for your comments and I look forward to lots more interesting stuff from you. All the best, Kip.

German armour penetration overstated? Hi, For those with my interests these have been good times. Not only have we got the stunningly realistic CM but when I asked Charles how he calculated his armour penetration figures he was kind enough to post up the name of the British Ordnance Board document he used so that I could obtain a copy. John Waters and Paul Lakowski were then good enough to chip in with the names of more research documents that would interest me, as I say good times. One of BTS’s claims to fame is that as a result of Charles’s work they use more accurate penetration figures than any other game and that part of this is that they are calculated on a “consistent basis” within any given nation and between the different nations. As with everything else they have certainly delivered in this department. However, when I went through the figures in detail I did find that the German penetration figures were a little generous, that Charles had been some what harsh on some US guns and when it comes to the poor old British 17pdr he had been spectacularly unkind. Given the data for the exact diameter of a projectile, the exact mass of a projectile and the velocity it is possible to calculate penetration figures on a “consistent basis”, which is what I have attempted to do. The reason you cannot use the official figures from the various nations is that they used different definitions of penetration and different qualities and types of steel plate as targets. Even within one nation’s figures there may be differences. It is also important to note that a penetration figure of 100mm for a given gun, at a given range, only means that 100mm is the average or midpoint in a large range of possible outcomes. In what follows the penetration figures are for a given gun at a range of 100m against steel plate at 30degrees from the vertical. I have used such a short range so that it is reasonable to use muzzle velocity as my figure for V in the formula I use. I make no attempt to calculate the penetration figures in the “raw”. What I mean by this is that my starting point, or constant in my calculations, is a given figure of Charles’s, say the penetration figure for the German 75mmL48 gun of 108mm and given this figure I calculate whether the figure Charles uses for say the British 17pdr is reasonable. I cannot use just one of Charles’s penetration figures as the constant in all my calculations because the formula I use does not handle changes in diameter accurately enough, in my opinion. For example for a gun such as the 57mm 6pdr I use as my starting point Charles penetration figure for the 50mm Pak38 and not the figure from the 75mmL48 gun, and so on. The three constants I use for different size guns are Charles’s figure for the 88mmL56 gun of 119mm, Charles’s figure for the 75mmL48 gun of 108mm and lastly for smaller guns Charles’s figure of 75mm for the 50mm Pak 38. The formula I use is the Milne-de-Marre formula, which handles penetration by WW2 APCBC rounds well. I will not bore people with the detail of how it works as I have posted this before but in outline this is how I go about things. I work out the energy delivered per square millimetre by the projectile from German 75mmL48 gun, call this figure a. This is not the “raw” energy but the energy modified for penetration of armour plate. I then work out a similar figure for the projectile from the American 75mm gun, call this figure b. At this stage remember that Charles’s penetration figure for the L48 is one of my constants, that is 108mm. I then divide b by a and multiply this result by 108. This gives me a result of 77. What this means is that given Charles’s penetration figure for the German L48 gun of 108mm, on a “consistent basis”, the penetration figure for the American 75mm gun should be 77mm. In fact Charles gives it a figure of 76mm, more than close enough. In conclusion it can be said that Charles’s figures for the American 75mm gun and the German 75mmL48 gun are consistent with each other, in my view (however little that may be worth).In the table below the first figure,next to the name of the gun, is Charles's penetration figure from CM. The second figure,for example 135 in the case of the 75L70 gun, is my "consistent basis" penetration figure.i.e given Charles figure of 108mm for the 75L48 gun in my view the penetration figure for the 75L70 gun should be 135mm. German guns. 50Pak38-- 75-- 75 75L48-- 108-- 108 75L70-- 139-- 135 88L56-- 119-- 119 88L71-- 177-- 171 US guns. 75mm-- 76-- 77 76mm-- 97-- 108 British guns. 6pdr-- 77-- 85 17pdr-- 118-- 135 The first thing that strikes me is that Charles's figures for the 75L70 are consistent with his figures for the 75L48 gun and equally so are his figures for the 88L71 gun when compared to the 88L56 gun. In the discussion there was about the penetration of the 88L71 gun I therefor go with Charles’s view that the official German figures for the L71 gun were overstated. (The reason that my figures for the 75L70 and 88L71 guns are slightly less than Charles’s is that the de-Marre formula is a little less generous than Charles’s formula with the increase in penetration as velocity increases.) When we move on to the Allied guns differences start to open up between Charles figures and my figures. Both the US76mm gun and the German 75L48 gun deliver near identical energy, modified for penetration, to the target per square millimetre yet Charles has given the German gun 11% greater penetration. The British 17pdr and the German 75L70 guns also deliver identical energy yet Charles gives the German gun 18% greater penetration. The 6pdr has also suffered. Whatever the actual reasons Charles has for the different figures “in effect” what he is saying is that US and British projectiles were of lower quality than German projectiles, in the case of the 17pdr very much lower quality. My view is that US and British projectiles are likely to have been of a very similar quality to German projectiles. By the second half of the war all the major players had done a huge amount of work on APCBC rounds. They all new all there will have been to know about such rounds. They also will have had lots of samples of German rounds to study going back two/four years. In short I think it highly unlikely that US and British projectiles of 1944 were of significantly less quality than projectiles from Germany. Before assuming any country had technology very much below the “going rate” I feel one needs to have “compelling and consistent” data to support that view. Others may have that data but I have not come across such evidence with regard to US and British projectiles. Before leaving you all alone I thought I would just include the penetration figures for some of the most common Russian guns as it only takes another ten minutes of schoolboy maths to produce them. The Russian figures are produced in the same way as the US and British penetration figures, i.e. on a “consistent basis” with Charles’s figures for the 50mmPak38, the 75L48 and the 88L56 guns. If you hold the view that Russian projectiles were of lower quality than German projectiles then you should decrease the following figures by whatever percentage you feel is appropriate. As before these figures are for penetration at 100m against 30 degree armour plate. The quality of the plate being the same as that used for Charles’s figures in CM. Consistent basis. Russian guns. 45mm,model42-- 66 57mm,model43-- 106 76.2mm,model42-- 81 85mm,model44- 120 As there often is discussion of the quality of Russian projectiles it would be a bit perverse to post figures on a “consistent basis” without giving an opinion on Russian ammunition quality. My starting point is that no one set of data from WW2 test firings should be given too much weight as one does not know the exact quality of the target plate in such tests, even if the surface hardness figure is given. It is also worth restating that there is a very large range of outcomes when dealing with armour penetration and therefor the test outcome one has the data for may not be an “average” figure over a large number of rounds. The normal assumption is that Russian projectiles were of lower quality than German and western ammunition. The main reason why this is normally assumed to be the case is that the “official” figures the Russians produced themselves and used in their wartime manuals showed lower penetration figures than one would expect given the energy delivered by their projectiles. However as is pointed out in a massive 1947 document I found in the archives of the Bovington Tank Museum “it is know that the Russians calculate their penetration of armour figures by a more pessimistic formula than that used by other powers”. In the document the British always give the above “health warning” with regard to the quoted Russian figures but at times they also give the British Ordnance Board’s estimate of what the true penetration figure is for a given gun on a western basis. When they do this the figures they come up with are slightly higher than the “consistent basis” figures I have given. They do discus Russian ammunition quality but only indicate that the Russian tungsten core ammunition was of lower quality than western ammunition. They are very specific about their reasons for reaching this conclusion. They claim that Russian APCR ammunition had a less efficient aerodynamic shape and that penetration would therefor fall off quicker. It is also worth noting that German test results on the BR350A APC round, fired from the Russian 76.2 Model42 gun and the T34/76 tank, showed it to have the same penetration as one would have expected from German ammunition delivering the same energy. The test results showed a penetration against 30 degree plate at 500m of 75mm. Given the velocity, mass and diameter of the BR350A round this is what one would have expected from a German round with the same specification. (John Waters kindly posted the figures regarding the BR350A round in another thread.) There is also evidence pointing to the fact that Russian ammunition was of lower quality than German ammunition and that therefor the figures I have given should be rounded down. The important point is that not all the evidence points one way. There is no certain, correct answer to the question of Russian ammunition quality. It will remain a matter of opinion and there will always be disagreements. (In my view this makes the subject even more interesting.) However my view is that over all there is more evidence suggesting Russian ammunition was of somewhat lower quality than there is suggesting it was of the same quality as western ammunition. I would round down the “consistent basis” figures I have given for Russian guns by between 5%-10% in order to give the most likely “actual” penetration figures for Russian guns. To round down the Russian figures by more than 10% would, in my view, be to ignore evidence such as the German tests of the BR350A and the views of the British Ordnance Board when considering these very questions. The British Ordnance Board of 1947 being better judges of APCBC ammunition than any of us can hope to be sixty years later. Thanks for your time, All the best, Kip. [This message has been edited by kipanderson (edited 10-01-2000).]

John, Yes, I am on to be included in the email, glad to be offered a place. When it comes to what Robert provided its interesting stuff. My own view of why the "official" German figure of 202mm may be so high is that it may well be actual test results against their own rather low quality 200mm plate. The Germans, like many others, did have a lot of production problems with such thick plate. It may have had a high hardness but still may have been of low quality throughout its entire thickness. i.e. the figure of 202mm may not be against plate of the same quality as the figure of 120mm for the L56 gun. Hence the figure of 202mm may be correct against the plate they tested it against but Charles 177mm/or my 172mm may be correct if measured against plate of the quality used to produce the 120mm figure for the L56 gun. There is more to plate quality than surface hardness. Of course this is only a hunch. All the best, Kip.