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	WW II Ballistics Tank Gun Penetration - UK


	The following is my choice of British gun penetration data. Penetration criteria in this case is 'The Thickness against Critical Velocity for Perforation'. This criteria is based on a 50% probability of a successful penetration. A successful penetration is at least 20% of the mass passing 'as a free missile' through the armor. The US and British 50% criteria are statistically the same. Tests of British guns produced firing graphs. Firing tables were made from these graphs and distributed to various boards.

Tank and Anti-tank Guns Penetration figures use American and British 50% success criteria.
Gun Type	Ammunition	Angle	Muzzle velocity	Penetration (mm)
Gun Type	Ammunition	Angle	Muzzle velocity	0 yd	250 yd	500 yd	1000 yd	1250 yd	1500 yd	2000 yd	2500 yd
OQF 2 pdr.	AP ¹	30°	2600 ft/s ( 792 m/s)	66	59	52	40	35	30	24
OQF 2 pdr.	AP ¹	0°	2600 ft/s ( 792 m/s)	90	78	67	48	41	35	26
OQF 2 pdr.	APHV ¹	30°	2800 ft/s ( 853 m/s)	72	64	57	44	39	33	25
OQF 2 pdr.	APHV ¹	0°	2800 ft/s ( 853 m/s)	100	86	75	54	46	39	29
OQF 2 pdr.	APCBC ²	30°	2600 ft/s ( 792 m/s)	63	60	56	49		43	38	32
OQF 2 pdr.	Littlejohn Mk I ¹⁰	30°	4200 ft/s (1280 m/s)	115	99	86	63	53	45
OQF 2 pdr.	Littlejohn Mk II ¹¹	30°	3750 ft/s (1143 m/s)	103	96	89	76	70	64	54
OQF 6 pdr.	AP ³	30°	2800 ft/s ( 853 m/s)	100		84	70		57	45
OQF 6 pdr.	AP ³	30°	2925 ft/s ( 892 m/s)	104		88	73		60	48
OQF 6 pdr.	APC ⁴	30°	2775 ft/s ( 846 m/s)	94		77	64		49	38
OQF 6 pdr.	APC ⁴	30°	2900 ft/s ( 884 m/s)	100		82	66		53	43
OQF 6 pdr.	APCBC ⁵	30°	2600 ft/s ( 792 m/s)	89		82	75		68	62
OQF 6 pdr.	APCBC ⁵	30°	2725 ft/s ( 831 m/s)	95		87	80		73	67
OQF 6 pdr.	Sabot ¹²	30°	4000 ft/s (1219 m/s)	151		134	118		103	90
OQF 17 pdr	APC ⁶	30°	2600 ft/s ( 792 m/s)	126		115	103		91	81
OQF 77mm	APCBC ⁹	30°	2575 ft/s ( 785 m/s)	128		118	110		100	93
OQF 77mm	Sabot ¹²	30°	3675 ft/s (1120 m/s)	182		165	149		134	120
OQF 17 pdr	AP ⁷	30°	2900 ft/s ( 884 m/s)	132		120	109		98	91	87
OQF 17 pdr	APC ⁶	30°	2900 ft/s ( 884 m/s)	132		120	109		98	87
OQF 17 pdr	APCBC ⁸	30°	2900 ft/s ( 884 m/s)	132	129	126	120	117	114	107
OQF 17 pdr	APCBC ⁹	0°	2900 ft/s ( 884 m/s)				162			139
OQF 17 pdr	APCBC ⁹	30°	2900 ft/s ( 884 m/s)	152		140	130		120	112
OQF 17 pdr	Sabot ¹²	30°	3680 ft/s (1122 m/s)	201		186	172		158	145


	Citations 1. British Ordnance Board 1944 Ordnance Quick Fire 2 pdr. A.P. shot graph OB/44/CV 28 2. British Ordnance Board 1943 Ordnance Quick Fire 2 pdr. A.P.C.B.C. graph OB/43/CV 4 3. British Ordnance Board 2/1/1944 Ordnance Quick Fire 6 pdr. A.P. graph OB/44/CV 25 4. British Ordnance Board 3/19/1943 Ordnance Quick Fire 6 pdr. A.P.C. graph OB/43/CV 2 5. British Ordnance Board 5/18/1944 Ordnance Quick Fire 6 pdr. A.P.C.B.C. graph OB/44/CV 38 6. British Ordnance Board 1943 Ordnance Quick Fire 17 pdr. A.P.C. graph OB/44/CV 7 7. British Ordnance Board 1943 Ordnance Quick Fire 17 pdr. A.P. graph OB/44/CV 10 8. British Ordnance Board Ordnance Quick Fire 17 pdr Est. Proc. No. 22834 9. British Ordnance Board 1944 Ordnance Quick Fire 77mm. & 17 pdr A.P.C.B.C graph OB/CV 44 10. British Ordnance Board 1944 Ordnance Quick Fire 2 pr. Littlejohn Mk I graph OB/44/CV 40 11. British Ordnance Board 1944 Ordnance Quick Fire 2 pr. Littlejohn Mk II graph OB/44/CV 41 12. CSAR core graph Critical Velocity graphs. 17 pdr APCBC 17 pdr APC 17 pdr AP 2 pdr projectiles 2 pdt AP 2 pdr projectiles 6 pdr projectiles

Armor Basis is Averaged and Normalized to RHA BHN 270 Penetration figures use 50% success criteria.
Gun Type	Ammunition	Angle	Muzzle velocity	Penetration (mm)
Gun Type	Ammunition	Angle	Muzzle velocity	100 m	300 m	500 m	1000 m	1500 m	2000 m	2500 m	3000 m
OQF 40mm Bofors	AP*	0°	2650 ft/s ( 808 m/s)	82	79	74	59	47	38	28	19
OQF 2 pdr	APHE	0°	2600 ft/s ( 792 m/s)	56	53	51	41	30	23	13	7
OQF 2 pdr	AP	0°	2600 ft/s ( 792 m/s)	76	68	60	43	32	22	13	8
OQF 2 pdr	AP*	0°	2800 ft/s ( 853 m/s)	82	76	67	49	35	27	19	12
OQF 2 pdr	APCBC	0°	2600 ft/s ( 792 m/s)	74	70	66	57	48	42	33	26
OQF 2pdr	Littlejohn Mk I	0°	4200 ft/s (1280 m/s)	125	113	99	73	51	35	25	15
OQF 2pdr	Littlejohn Mk II	0°	3750 ft/s (1143 m/s)	111	105	99	85	72	63	55	47
OQF 6 pdr	AP	0°	2800 ft/s ( 853 m/s)	104	96	88	70	54	42
OQF 6 pdr	AP	0°	2925 ft/s ( 892 m/s)	113	106	98	81	66	53
OQF 6 pdr	APC	0°	2775 ft/s ( 846 m/s)	104	96	88	70	54	42
OQF 6 pdr	APC	0°	2900 ft/s ( 884 m/s)	109	102	94	77	60	45
OQF 6 pdr	APCBC	0°	2600 ft/s ( 792 m/s)	100	95	91	82	72	65
OQF 6 pdr	APCBC	0°	2725 ft/s ( 831 m/s)	106	102	97	88	78	70
OQF 6 pdr	Sabot	0°	4000 ft/s (1219 m/s)	161	153	145	127	109	94	77	62
OQF 77mm	APC	0°	2600 ft/s ( 792 m/s)	143	137	131	116	101	91	78	66
OQF 77mm	APCBC	0°	2575 ft/s ( 785 m/s)	143	137	131	117	104	98	90	84
OQF 77mm	Sabot	0°	3675 ft/s (1120 m/s)	198	193	186	160	143	123	103	83
OQF 17 pdr	AP	0°	2900 ft/s ( 884 m/s)	151	143	137	123	109	97	84	71
OQF 17 pdr	APC	0°	2900 ft/s ( 884 m/s)	151	143	137	123	109	97	84	71
OQF 17 pdr	APCBC	0°	2900 ft/s ( 884 m/s)	172	166	161	148	136	125	114	103
OQF 17 pdr	Sabot	0°	3950 ft/s (1204 m/s)	233	226	219	200	182	162	143	123
OQF 25 pdr	AP	0°	1550 ft/s ( 472 m/s)	79	74	69	61	54	49
OQF 25 pdr	AP	0°	2000 ft/s ( 610 m/s)	104	98	91	76	65	56
OQF 95mm/L20	HEAT	0°	1650 ft/s ( 503 m/s)	127	127	127	127


	Entire data collection each individually normalized to RHA hardness of BHN 270 and US NBL criteria. British MQ homogeneous armor seems to be equivalent quality to 250 BHN in testing. * AP 2-pdr shot may shatter vs 2 x caliber armor above 2600 ft/s. 2 pr APHE produced 1936 to 1938. 2 pr AP produced from 1938 with HE filler replaced by inert material. 2 pr AP supercharge began September 1942. 2 pr APCBC began production in December 1942. 2 pr Littlejohn Mk I began production January 1943. 2 pr Littlejohn Mk II began production May 1944. There are a few anomalies in the data like why does the OQF 17-pounder have considerably better penetration for the APCBC than the APC and AP? A windscreen and AP cap should theoretically reduce the penetration slightly. But early war tests were sometimes revised later war because methods changed or ballistics measurements improved. To normalize data I had to dismiss some early war data in favor of revised late war data. NAAB2 does include the 3" OQF 17 pdr in British gun class 13. Change shell quality to 0.985 and set to meters. Armor deck British post 1930. The Ballistics page produces result very close to the above table for 17-pdr APCBC.