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Hollow charge ammunition for the M1 75 mm pack howitzer?

Discussion in 'Allied Heavy Weapons' started by Riter, Apr 24, 2020.

  1. Riter

    Riter Active Member

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    I'm reading Koskimaki's Battered Bastards of Bastogne. He mentions the 463 Parachute Artillery Battalion and its small 75 mm pack howitzers knocking out 8 out of 10 German tanks at Bastogne. They used hollow charge ammunition to perform the task. I never heard of such a thing for those little guns (we had one in the SF Presidio that was used ceremonial purposes). Can anyone tell me more about the ammunition? I know about hollow charges, but for a 75 mm howitizer?
     
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  2. Kai-Petri

    Kai-Petri Kenraali

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    75 mm is not a small gun. the other thing what German tanks coukd tahe Pz II-IV not Tiges which had 10 cm of protection.Hollowv chage? does not sound tank ammo to me.
     
  3. Riter

    Riter Active Member

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    It was the M1 75 mm howitzer. Not small enough for me to stuff down my trouser pocket and too big for me to load onto a trailer on my own. One in the hands of the US Marines:Here is a picture of in being [​IMG]

    Here is a picture of in being used by Nationalist Chinese troops:

    [​IMG]

    You can see it is a lot smaller than the standard M2 75 mm field howitzer. As for the hollow-charge ammunition, I'm just reciting that from the book and asking for verification that such ammunition was available for the M1 in WW II. BTW, we had a section (2 guns) at the Presidio of San Francisco. They were working pieces and were used for memorial events.

    Contrast the above to the M2 105mm howitzer

    [​IMG]
     
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  4. von Poop

    von Poop Waspish WW2|ORG Editor

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    Hogg: Three ammunition types: HE M48, Chemical M64 & HEAT M66 (The HEAT being the only fixed round).

    M66 HEAT spec: M62 base-fused, 1lb Pentolite, Plate penetration up to 3.5" at any range.

    Remarkable little gun, isn't it.
    There's a group of US airborne reenactors that we've watched do a fantastic display with one on several occasions. Quite the rapid fire punch for such a diminutive item.
     
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  5. Kai-Petri

    Kai-Petri Kenraali

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    Gret photos Riter. However considering the shooting betweeen Pz IV and Tiger might not do a thing
     
  6. Riter

    Riter Active Member

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    Concur. 17 pdr FTW, but I want to know if hollow charge was available. It's the first time I've heard of it.
     
  7. Riter

    Riter Active Member

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    thanks.
     
  8. GaryJKennedy

    GaryJKennedy New Member

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    If you search for the "Catalog of Standard Ordnance Items, Volume 3" you can find the details for the M66 shell described above.

    "This projectile embodies the 'hollow charge' or 'Munroe' principle. It is a remarkable armor-piercing round and will penetrate approximately 3&1/2-inches of armor."

    Gary
     
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  9. Terry D

    Terry D Active Member

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    In August 1944 the US Army in France conducted a series of tests at Isigny to determine the effectiveness of various anti-tank rounds. The types tested were the British 17-pdr, US 75mm (M3 gun, M61 AP), the US 76mm, and 75mm howitzer M66 HEAT. I don't have all the details at hand (Nicholas Moran covers the tests on his site) but the tests did determine that the 75mm M66 gave much better performance than the 75mm M61. If I recall, there were cases in the Pacific where Marine tankers fired the 75mm M66 from the M3 guns in their Shermans, presumably in an effort to get better penetration against Jap bunkers. At least one British armored regiment in NWE (lost the reference) experimented with the M66 in its Shermans as well. Maybe they had to use the M66 in cases for the 75mm gun, don't know. Anyway, the M66 seems to have offered at least a possible emergency option to upgrade the performance of the M3 gun, and in light of the difficulties the Allies had with German armor in NWE I am a little surprised that the option was not taken on any large scale.
     
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  10. harolds

    harolds Member

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    Hollow charge shells are effective IF they can be detonated at the right distance from the target surface AND while (more or less) perpendicular to the target surface. The problem firing them from cannons is that the shell's rotation tends to dissipate the explosive jet.
     
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  11. RichTO90

    RichTO90 Well-Known Member

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    Terry, the second Isigny test was 19-21 August and was just of the 17-pdr and 76mm, the former with AP and Sabot and the latter with APC and HVAP. The first Isigny test was 12-30 July, testing:

    Launcher, Rocket, AT, 2.36″ – Rocket, AT, 2.36″, M6A1
    Launcher, Grenade, M8 – Grenade, AT, M9A1
    37mm Gun, M6, Mounted on Light Tank, M5A1 – APC M51
    40mm Gun, M1, AA – AP M58
    57mm Gun, M1 (ATG) – APC M86, and Sabot
    75mm Gun, M3, mounted on Medium Tank, M4 – APC M61 and HEAT M66 (Special)
    3-inch Gun, M5, mounted on Motor Carriage, M10 – APC M62 with BDF M66A1, and AP M79
    90mm Gun, M1A1, AA – AP M77
    105mm Howitzer, M4, mounted on Medium Tank, M4 – HEAT M67

    The findings for 75mm Gun was:

    6) 75mm Gun, M3, mounted on Medium Tank, M4

    a) APC M61 will penetrate the sides and rear of the ‘Panther’ Tank up to 1500 yards. APC M61 at 200 yards will not penetrate the front armor of the ‘Panther’ Tank.

    b) HEAT M66 (Special) will not penetrate the front glacis slope plate at 500 yards (see assumption made in paragraph 1c).

    No, the Marines to my knowledge did not use M66 as a substitute for APC M61. That may be a conflation of Tarawa, where the surviving Medium Tanks M4 on Betio ran out of standard 75m M48 HE and M61 APC for Gun M2 and M3 and substituted 75mm M48 HE for Howitzer M1, M1A1, M2, and M3. The thing is the howitzer complete round is 3.1 inches shorter, so they had to use a stick as a ramrod to get it to seat in the chamber...and the flashback was apparently seriously awesome inside the turret. :D It also reduced accuracy at anything other than very short range, so it would be true desperation to try to do the same with the howitzer's M66 round. M66 was never manufactured for the 75mm gun, because the higher velocity spin severely degraded the penetration.
     
  12. Terry D

    Terry D Active Member

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    Thanks, very enlightening. It explains a lot.
     
  13. Carronade

    Carronade Ace Patron  

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    The penetration of HEAT should be independent of range, should it not? If you hit X armor at Y angle it will penetrate or not.

    As a couple of people have mentioned, spinning decreases the effectiveness of a shaped charge. Presumably it was still better than the penetration of a solid shot from a low-velocity howitzer. The French came up with an interesting concept for the 105mm gun on the AMX-30; the hollow charge was surrounded by bearings so it did not spin although the shell did.

    Another interesting concept was HESH (High Explosive Squash Head) or HEP (High Explosive Plastic), a thin-cased shell filled with plastic explosive with the fuze at the base. When it hit, the plastic would spread out on the surface of the target and then explode, apparently quite devastating, and effective against heavy or light armor, buildings, whatever. It was commonly used in recoilless rifles like the British 120mm BAT series.
     
  14. RichTO90

    RichTO90 Well-Known Member

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    Yes, of course...as long as fuze operation is correct and stand-off distance is optimal, which was the biggest problem in early heat warheads. Did I say anything different?

    Meanwhile, the report should have said "at any distance", but that should be obvious. The only "hollow charge" I know of in the American arsenal that could penetrate the front of the Panther was 105mm M67.

    Indeed, as a number of German Panzer from 15. Panzergrenadier-Division found when they encountered the 466th PFAB on 25 December 1944.

    Yep. Unfortunately developed postwar.
     

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