HESH vs Spaced Armour

Soviet live fire experiments with HESH fired from a 105 mm tank gun and a 106 mm recoilless rifle were published in the Armoured Journal (Bronetankoviy Vestnik) as a part of a study on tank protection. In this study, various types of armour layouts were simulated by placing thin 2P steel or aluminium alloy plates of various types, representing skirt armour, at a distance of 330 mm away from a thicker 2P steel plate, representing the side of the tank's hull. The shots were fired from 100 meters. Here are the results.

Caliber (mm)	Angle (deg)	Impact velocity (m/s)	Armour thickness (mm)	Damage		Normaliza-tion angle of fragments
				First plate	Second plate
105	0	634	5+20 (Steel)	Breach 650x400 mm	Breach 240x300 mm*	0
105	0	615	5+80 (Steel)	Breach 500x550 mm	Dents from fragments up to 12 mm deep over 350x400 mm	0
105	0	605	5+20 (Steel)	Breach 650x480 mm	Dents from fragments 10-12 mm deep over 500x550 mm	0
105	0	614	10+20(Steel)	Breach 600x600 mm	Plate cracked, two penetrations, dents from fragments over	0
105	0	722	10+20(Steel)	Breach 500x400 mm	Three penetrations, dents from fragments over 350x370 mm.	0
105	0	617	10+30(Steel)	Breach 550x600 mm	Dents up to 7 mm deep over 370x400 mm.	0
105	0	607	30 (ABT-101) + 20 (Steel)	Plate cracked	Dents up to 8 mm deep over 450x400 mm, 706 mm long crack.	0
105	0	615	5 (AMG-6) + 80 (Steel at a 60 deg angle)	Penetration 170x110 mm	Plate cracked**	-
105	45	606	5+20 (Steel)	Breach 780x350 mm	Plate cracked. Dents from fragments up to 10 mm deep over 550x500 mm	15-25
105	50	606	5+20(Steel)	Breach 650x290 mm	Plate cracked. Dents up to 11 mm deep over 550x500 mm	20-25
105	60	640	5+20(Steel)	Breach 550x340 mm	Dents up to 13 mm deep over 500x620 mm.	20-30
105	60	635	10+20(Steel)	Plate cracked	40x40 mm penetration, dents from fragments over 350x500 mm.	-
105	60	599	13(ABT-101) + 20 (Steel)	Breach 500x480 mm	Dents up to 100 [sic] mm deep over 500x490 mm.	20-30
105	0	489	5+45(Steel)	Breach 620x480 mm	Dents up to 5 mm deep over 600x560 mm.	0
106	60	489	10+20(Steel)	Plate cracked	Breach 310x170 mm, dents from fragments over 430x400 mm.	35-40
106	60	489	20+45(Steel)	Breach 800x550 mm with spall fragment	Dents up to 15 mm deep from fragments over 360x380. 20 mm dent from spall fragment.	30-40