17 pounder APDS - & 17 pdr in general.

Discussion in 'Weapons, Technology & Equipment' started by mollusc, Oct 21, 2008.

  1. mollusc

    mollusc Member

    Extracts from a US report:


    U.S. Army Firing Test No.3
    U.S. Army Firing Tests conducted August 1944 by 12th U.S. Army Group at Isigny, France.


    <CENTER><TABLE style="BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=600 border=0><TBODY><TR><TD width="100%">Board of Officers
    APO 655


    30 August 1944
    SUBJECT: Final report of board of officers appointed to determine comparative effectiveness of ammunition of 76mm gun and 17pdr gun.
    TO: Commanding General, Twelfth Army Group.
    1. The board convened pursuant to the attached order at the firing range established by First U.S. Army near Isigny, France at 1030 hours, 19 August 1944 and conducted firing tests against the front plate of German Panther Tanks. The firing was continued, as the weather and the availability of target tanks permitted, on 20 and 21 August 1944. Because of the urgency of the test, a preliminary report, dated 21 August 1944, was submitted on 22 August 1944.

    </TD></TR></TBODY></TABLE></CENTER>

    The 17pdr guns were fired by two superior British enlisted gunners. The 76mm gun was fired by two officers with considerable test firing experience.

    Forty-two (42) rounds of 17pdr SABOT were fired and only 57% [24 rounds] were hits.

    Firing was done at between 200 and 600 yards at a stationary Panther.

    It was suggested that the APDS ammunition was sub-standard.

    Does anybody have any information on either the accuracy of the APDS round or how widespread it's use was after it's introduction in August '44 please?
     
  2. Bodston

    Bodston Little Willy

    The 17-pdr APDS round was not very accurate at long ranges. This taken from Mark Hayward's 'The Sherman Firefly' The Firefly was not a universal remedy. The 17-pdr's HE performance was limited and at longer ranges its accuracy with the more effective sabot ammunition left a lot to be desired. Trials conducted in mid-1944 state that the useful range of APC ammunition was 900 yards (822 metres) while that of APDS was only 450 yards (411 metres). The files show that, while at 400 yards (365 metres) APC could be expected to hit a standard size target some 90.5 per cent of the time, APDS only achieved the same performance 56.6 per cent of the time. At 1,500 yards (1,371 metres), the comparative figures were 25.4 per cent and 7.1 per cent. It seems that ammunition quality improved over time, but the accuracy of the 75mm M3 gun was still admired and in demand up until the end of the war.

    Those range comparisons in full..

    400 yds APC hit 90.5% APDS hit 56.6%
    600 yds APC hit 73.0% APDS hit 34.2%
    800 yds APC hit 57.3% APDS hit 21.9%
    1000 yds APC hit 45.3% APDS hit 14.9%
    1500 yds APC hit 25.4% APDS hit 7.1%
     
  3. James S

    James S Very Senior Member

    Certainly new info to me - thank you , food for thought .
     
  4. Tom Canning

    Tom Canning WW2 Veteran WW2 Veteran

    Mollosc / Bodston -
    Just as well we never saw the APDS round until the last gasp in Italy - the APC was good enough for us,on the six pounder - we never could get near enough to do any damage
    Cheers
     
  5. Paul Reed

    Paul Reed Ubique

    Were these tank mounted weapons or anti-tank guns?
     
  6. Bodston

    Bodston Little Willy

    There is some more about accuracy in Mark Hayward's 'The Sherman Firefly' who is in turn quoting from two wartime documents, WO 291/1263 and WO 165/135 recorded on 22nd September 1944. Further to this he quotes from a conversation with Sgt. Jack Moat DCM (1st RTR, 7th Armd. Div. 1940-45) on 2nd November 2000 as published in 'Tank, the journal of the Royal Tank Regiment'. These trials were conducted with two tanks - a IC (T263317) and a VC (T148506). The report does state that these figures might be sympathetic "... a maximum range of engagement at which every second round will hit appears under these conditions to be a generous one". It was noted (referring to targets such as hull down tanks) that using APDS "... there is no use in attempting to pin-point vital zones in targets at ranges over about 200-300 yards". This is not a range anyone would want to be in a Sherman against any late-war German tank. "APC shot does not possess sufficient accuracy for pin-point shooting at vital zones in targets at ranges over about 300 yards". The report did not consider the tests with APC as typical and that "... the accuracy of fire with APC can be better than that obtained in this and the preceding trial". "The first batch of 17-pdr appear not only to be innaccurate, but also have a dissapointing performance". Contrary to this and other reports, Sergeant Moat regarded the 17-pdr as very accurate and did not agree with the accuracy problems. He conceded that the HE round was not as good as the 75mm M3. The 17-pdr never let him down and always did what he asked of it. He thought the Firefly was the best tank he saw service in and the 17-pdr a reliable high performance weapon, especially compared to the inadequate tanks he put up with in earlier campaigns.
     
  7. mollusc

    mollusc Member

    The 17-pdr APDS round was not very accurate at long ranges. This taken from Mark Hayward's 'The Sherman Firefly'

    Those range comparisons in full..

    400 yds APC hit 90.5% APDS hit 56.6%
    600 yds APC hit 73.0% APDS hit 34.2%
    800 yds APC hit 57.3% APDS hit 21.9%
    1000 yds APC hit 45.3% APDS hit 14.9%
    1500 yds APC hit 25.4% APDS hit 7.1%

    Thankyou for this information - very interesting stuff. I must admit I'm very surprised how low the percentages are, for both APC and APDS, although it will all depend on what is meant by "standard target size". I'm assuming it's something like 3x2 yrds ie approximating the front view of a tank. If that is so, then these figures are awful.

    I'd always assumed early APDS was inaccurate because it was "early" technology and still to be refined, but I'd assumed 17pdr APC would have been more accurate (versus 75mm or 6 pdr) just because of the extra velocity, but obviously things aren't always so simple.
     
  8. kfz

    kfz Very Senior Member

    Thankyou for this information - very interesting stuff. I must admit I'm very surprised how low the percentages are, for both APC and APDS, although it will all depend on what is meant by "standard target size". I'm assuming it's something like 3x2 yrds ie approximating the front view of a tank. If that is so, then these figures are awful.

    I'd always assumed early APDS was inaccurate because it was "early" technology and still to be refined, but I'd assumed 17pdr APC would have been more accurate (versus 75mm or 6 pdr) just because of the extra velocity, but obviously things aren't always so simple.


    I think AP shot is pretty typical figures arnt they?

    57% chance of first round hit at 800 yrds. 75% of first round hit typical combat range. Seems about right to me.

    As for APDS I knew its not as accurate as conventional rounds which still holds true today I guess, never going to be. Not only cos of the early days of the technolagy and the difficult manufactuing requiered but the maths of a projectile that changes mass half way through its trajectory must be a nightmare, how the hell you even aim it I dont know...

    Kev
    Kev
     
  9. mollusc

    mollusc Member

    I think AP shot is pretty typical figures arnt they?

    57% chance of first round hit at 800 yrds. 75% of first round hit typical combat range. Seems about right to me.

    As for APDS I knew its not as accurate as conventional rounds which still holds true today I guess, never going to be. Not only cos of the early days of the technolagy and the difficult manufactuing requiered but the maths of a projectile that changes mass half way through its trajectory must be a nightmare, how the hell you even aim it I dont know...

    Kev
    Kev

    But these aren't first round hit percentages, that's the thing. If they were, the numbers would be ok.

    These percentages are the chance of a shell hitting the target given that the gun is already laid properly and zeroed in, and the range is known. Look at the US report again, 24 of 42 APDS rounds hit the (stationary) target at 200, 400 and 600 yard ranges. At those ranges and with theoretically minimal drop-off (given APDS velocity) you can aim through the tube! So any misses will be down to the ammunition itself.

    Actual combat percentages would be lower still, and then consider moving targets...

    I think APDS today is deadly accurate, the Chally 2 fires them out at 1,600m/s and they seldom miss. There is a great youtube vid here... http://uk.youtube.com/watch?v=pKe3c75mH5c

    The SABOT for APDS was either pot or petal, (ie it was dragged off the back of the shell after leaving the barrel by air resistance in the case of pot, or discarded radially in the case of petal). Theoretically it can be done without affecting the flight of the shell. Obviously not in 1944.
     
  10. von Poop

    von Poop Adaministrator Admin

  11. Drew5233

    Drew5233 #FuturePilot 1940 Obsessive

    DCM

    Immediate.

    Sergeant Moat was in charge of a Sherman tank during an action to clear the enemy from the area of Corso near S'Hertogenbosh on 30th September 1944.

    Sergeant Moat's tank was in a position of observation directing artillery fire when it was observed by an enemy OP and heavy and accurate enemy mortar fire was brought down on it. Sergeant Moat was hit in the head by splinters from a mortar bomb which burst against the tank aerial and the tank refused to start up. Sergeant Moat then climbed out of his tank and attempted to hitch the tow rope of another tank on by himself. He was unable to do this and so he collected two members of his crew to help him, both these men were killed by mortar fire while attempting to fix the two rope and so Sergeant Moat finished the job himself. By this time a Sapndau had opened up on him as well as mortar fire so he climbed back into his tank and engaged the Spandau himself with his Browning and destroyed it. He then ordered the tank to be towed away and went forward on foot to try and deal with the Mortar OP.

    He located the OP and captured it himself taking 12 P/W. This action put a stop to the mortar fire and undoubtedly saved many lives. This NCO's aggressive spirit and cool courage were an inspiration to his troop and by his action he opened the way for the advance to continue.

    Recommended for MM.

    Gazetted 1.3.45
     
  12. TomTAS

    TomTAS Very Senior Member

    Hi All,

    A Good Arnhem Veteran friend of mine was on the 17 Pd the one which was left north of the rail line at Wolfheze so some time back I took him down to Middle Wallop.. Shamus got to stand in a Hamilcar after 60 odd years which he enjoyed a lot
     

    Attached Files:

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  13. von Poop

    von Poop Adaministrator Admin

    Looking for something Chris C asked for, pottered onto an FAJ article from 1944 on 'modern' AT guns that includes this:
    FIELD ARTILLERY JOURNAL—March, 1944

    Annotation 2020-01-19 165010.jpg

    Wonder how much veracity in that 'same day as Tiger' comment?
    Doesn't seem right, but 'saw action' a flexible term.
    What's Tigger? Late August '42? Leningrad?

    Suppose 'Pheasant' 17pdrs might have engaged around then, but pretty sure (without having checked) they were later. Don't have enough info on when 17pdrs first fired in anger.
    Presumably an example of an allied commentator's limited contemporary view of the Eastern front?
     
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  14. Chris C

    Chris C Canadian Patron

    Well if that's from 1944, it's entirely possible that they didn't accurately know when Tigers were first fielded against the USSR. I know I have Forty's Tiger Tank Battalion book in the other room but I'm busy at the moment. Will post later if no one else does.
     
  15. Don Juan

    Don Juan Well-Known Member

    One of the problems of early APDS was that it tended to leave deposits in the barrel, so that once you fired an APDS shot, the accuracy of your subsequent rounds was likely to be severely affected, whatever the type of round. APDS also accelerated barrel wear, which had an enormous influence on accuracy. Then there was the phenomenon of barrel droop over time, which was obviously more of an issue with longer guns. One of the biggest initiators of barrel droop was rain, so that the longer a tank was out in the rain, the less accurate its gun would become.

    There are so many aspects to accuracy it is mind-boggling, and most of what is commonly bandied about only touches the surface of the subject.
     
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  16. idler

    idler GeneralList

    The Chieftain's view:

     
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  17. Sheldrake

    Sheldrake All over the place.... Patron

    The Americans were correct to highlight the poor accuracy of the 17 pounder. Nick Moran may be right to claim that the US 90mm was a better anti tank gun (and the 3.7" Gun might have been for us)

    However,

    The 17 Pounder with APC and 6 Pounder APDS were both available in jun 1944 for D Day and the battles ashore. The US 76mm and 90mm SP were not.

    The Sherman 75mm could not penetrate the Tiger armour at any aspect or the Panther frontal armour at any range. However inaccurate the 17 pounder was it was a gun that could KO a tiger or panther. It might take four shots but it would do the job.
     
  18. m kenny

    m kenny Senior Member

    I think they mean the first time the Tiger was in action in Tunisia
     
  19. Listy

    Listy Well-Known Member

    Not surprised the 90mm M1 was better than the 17Lbr. After all its only 76mm vs 90mm. It's also significantly bigger. A better comparison is with the 3.7in (Eg: 94mm), and they did that during the war, and the 90mm was terrible:
    [​IMG]
    [​IMG]

    Now onto the APDS.
    One question, all these measurements etc etc etc, which APDS round are we talking about? the Mk.I, II or III? These had differences in construction, types of sabot and even doing stuff like changing the centre of balance to improve the accuracy. Yes I'll agree it was less accurate than a normal shell, but how much less accurate in which version?
    I do keep meaning to attack this problem, but workload keeps putting it under "nice to have".
    Also Moran puts a lot of emphasis on the US trails. I've got a document where the British tested some US kit, a Bazooka, and spent the day shooting it and couldn't get it to hit the target. So one wonders how much comes down to the experience of the guys using the weapon in the end.

    Finally, you'll see a lot of theories about why the APDS round is in accurate. I've seen the suggestion that it was the fault of the muzzle brake, the all burnt distance up the tube was too high, the gun started vibrating and a few others. I suspect nearly all of these are wrong simply because of the question "so why doesn't this happen when you fire an AP round?" It has been suggested to me by a colleague, that the problem comes from the breech. Look at the shape and size of the APDS and AP projectiles. If the case is in the gun, the the AP round is engaged with the rifling, and thus will act in a consistent supported manner throughout the firing sequence. The APDS round is shorter and there's a gap between the rifling and the head of the projectile. Thus it will engage in a different inconsistent way, after crossing the gap on each shot.
     
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  20. Sheldrake

    Sheldrake All over the place.... Patron

    Yes. Pemberton notes that the 17 pounder was in then field just in time to face the first tiger tanks at Robaa, but they were stopped by 6 pounders which penetrated the Tiger's 80mm side armour at 500-900 yards range. (p162) Later 17 pounders took on Tigers in the Medjerda area standing off at 1500 yards and engaging 1st Division infantry. (P163)

    The big issue is the psychological effects of these weapons on then soldiers that used or faced them.

    The 17 pounder was effective but unpopular as a towed equipment due to its extreme vulnerability. (The unarmoured Quad Field Artillery Tractor exposed detachments to mortar fire on the move and it took up to 12 hours to dig a big enough hole to hide the gun.) The gunners who served the SP 17 pounder variant of the M10 seem to have been very confident and shared little of the inferiority complex of the British and US armoured crews. They knew they had a gun that could KO the heaviest German tank, even though their own armour was paper thin.

    APDS ammunition gave 6 pounder detachments a lot of confidence in their ability to take on tanks that on paper might simply roll over them. Before D Day 50th Div Anti tank gunners were shown a demonstration of APDS to demonstrate that it worked. The RA anti tank gunners at Rauray 1 July 1944 used all their APDS ammunition. It must have taken a lot of guts to manhandle a 6 pounder 300 yards to get a good firing position. It might have helped top know that the Gun would KO the tank if hit.
     
    Last edited: Jan 20, 2020
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