"TO: Commanders of Artillery of Rifle Corps, Rifle Divisions, and Artillery Regiments
29th Rifle Corps only
On the causes of premature detonation of 122 mm HEAT rounds
Several cases of premature detonation of HEAT (armour burning) ammunition in barrels of model 1938 122 mm howtizers with the subsequent destruction thereof have been recorded in 1944. Investigations show that in half of the cases firing was done with the full propellant charge instead of #4 charge as required by the firing tables for HEAT ammunition.
To execute the orders of the Artillery Commander of the Front, the Commander of Artillery of the Army orders that:
All personnel of artillery units armed with 122 mm howitzers must be instructed that HEAT (armour burning) ammunition must be fired with propellant charge #4 only. It is categorically forbidden to use the full charge or charges ##1, 2, or 3, as premature detonation in the gun barrel is possible.
Chief of Staff of Artillery in the 48th Army, Colonel Shestoperov
Deputy Chief of Staff of Artillery in the 48th Army, Guards Major Deriy
January 6th, 1945"
...sounds like they had some janky fuzes in their HEAT shells all right.
ReplyDeleteThe M-30 by nature was a low velocity artillery piece, not a anti tank gun. The fact that thee HEAT round required a reduced round meant it had about the same velocity as a pistol. Imagine telling a artillery crew they must hit a moving tank, with a reduced charge round.
ReplyDeleteIt worked for Tom Hanks, didn't it? ;)
DeleteThe M-30 was never meant for anti-tank work, so if you have to fire HEAT directly then something has gone terribly work. Unfortunately, this probably means that if the tank is moving, it's moving towards you, which I guess makes it easier to aim.
Peter I just assumed the HEAT round was a last ditch round in case tanks broke through the lines and surprised the gun crew.
DeleteI think that's a good assumption. I previously posted another document where an order is given to use HEAT more, so they shoot it at bunkers or even at field fortifications sometimes. This was in early 1945, so German heavy tanks that would need this kind of ammunition weren't really common anymore.
DeleteUnfortunately the report doesn't give the muzzle velocity of a #4 charge. Wiki gives the HEAT shell MV as 335m/s. The closest firing table I can find for model 1938 122mm O-462A shell with a MV of 334 m/s.
ReplyDeleteThe manual that I have doesn't have HEAT mentioned in the main body. There is an appendix for HEAT, but it doesn't have velocity :(
DeleteIt's 341 m/s (source: https://pamyat-naroda.ru/documents/view/?id=451216306&backurl)
DeleteM-30 had 8 charges, plus the base charge? Is charge #1 full charge? I'm confused why they're mentioned separately.
ReplyDeleteFull and #1 are different. #1 charge is actually the second most powerful.
DeleteHere is the page from the manual. Charges are composed of two components: a base charge and up to 8 additional charges. The full charge is made up of the base charge, 4 additional in the upper portion of the casing, and 4 additional in the lower portion of the casing. Each subsequent reduction removes one additional charge, first from the upper, then from the lower, until the weakest charge (#8) is just the base charge.
Deletehttps://i.imgur.com/QiXGPB4.png
DeleteThe HE shell weighed 21.75 kg. where the HEAT shell was only 13.2 kg so would have a better MV than the HE shell with 4 charges. Though the nose of the HEAT shell is not as aerodynamic as the pointy nosed HE shell.
ReplyDelete