Tank Armaments

Specification and Armor Penetration of the Soviet Tank Guns

2009-10-14T09:48:16Z

I. Specification

Gun Model	Calibre, mm	Bore Length, clb	Elevation	Max. Range, m	Weight of Pendulous Elements, kg	Weight of Recoil Elements, kg	Normal Recoil Length, mm	Max. Recoil Length, mm	Loading	Practical ROF, shot/min
TNSh	20	82.4	-5° +27°	6,800	68	?	?	?	automatic	200
PT-23TB	23	?	-5° +27°	9,000	?	?	?	?	automatic	over 300
ZIS-19	37	66.7	-5° +30°	~10.000	?	73	?	?	single	8-15
Modernized "Hochkis"	37	20	?	?	103.8	?	?	?	single	5-6
PS-2	37	45	?	?	100	?	?	?	single	6-8
20K, 20Km	45	46	-6° +22°	~4,200¹	313	113	240-270	278	single	7-12
VT-42/43	45	68.6	-5° +25°/+78°	?	322	149	288	285	single	9-10
ZIS-4	57	73	-5° +30°	12,500	?	?	350-380	395	single	6-10
KT	76.2	16.5	?	?	540	?	?	?	single	5
PS-3	76.2	20.5	?	?	614	?	?	?	single	11-12
L-10	76.2	23.7	?	?	641	?	?	?	single	12
F-32	76.2	31.5	?	?	770	?	?	?	single	8
F-34, ZIS-5	76.2	41.6	-5° +28°	11,200	1,155	538	320-370	390	single	4-8¹
S-54	76.2	58	-5° +30°	?	1,390	?	?	400	single	3-5
D-5T, D-5S	85	51.6	-5° +22°	12,700	1,500	980	270-310	330	single	5-8²
ZIS-S-53	85	54.6	-5° +25°	12,900	1,150	905	280-320	330	single	6-10
ZIS-6	106.7	48.6	?	?	?	?	~600	?	separated⁴	3-4
D-10T, D-10S	100	53.5	-3° +18°	16,000	2,257	1,538	550	650	single	4-6
U-11	121.92	22.7	-2° +22°	?	?	?	590	680	separated	2-3
D-25T, D-25S	121.92	43	-2° +20°	14,200	2,588	1,850	580	660	separated	1.2-2.5
S-41	152.4	27.68	-3° +18°	?	~2.300	?	590	650	separated	1-2

¹ This is the tabular data range.
² The practice rate of fire of the T-34 was 3-5 shots per minute due to unsuccessful ammo layout.
³ The rate of fire during movement didn't exceed 4 shots/min; the ROF in stationary position on motionless target 10 shots/min.
⁴ Initially projected to be single loading ammo, but it was realized to be unsuccessful.

II. armor penetration¹ of the Soviet tank guns

This table is mostly based on data from the NII-48 (Research Lab #48) in 1942-1945. These data are different from widespread penetration data but values presented here seem to me more accurate and often confirmed by after-trials reports. Unfortunately, the armor quality (hardness etc) usually missed in those reports, so I cannot reveal it's real quality. All what was mentioned is "homogenous hardened armor" or simply "homogenous armor" and nothing more.

The tabular data were theoretical and were calculated by method of ARTKOM (Artillery Committee). This method was accepted in 1939 and its final result depended of two values:
- The Limit of the Through Penetration (LTP) when a whole projectile penetrate the armor and was found behind the armor plate.
- The Breaking Point of the Back Surface (BPBS) when a projectile didn't penetrate the armor but the back surface of the armor plate happened to be damaged.

The armor counted to be penetrated if at least 75% of a projectile's fragments happened to be found behind the armor plate. Most of the Soviet armor penetration tables based on this value. Curiously, but the German way of calculation the armor penetration was based on 50% penetration. That's why the Soviet and the German penetration values are so different.

Also, it is important to understand that realistic penetration values in 1941-1943 was reduced significantly due to low quality ammo.

Gun Model	Ammo Type	Muzzle Velocity, m/s	Angle	Range, m
Gun Model	Ammo Type	Muzzle Velocity, m/s	Angle	50	100	300	500	1,000	1,500	2,000
20 mm TNSh	AP with tungsten carbide core	817	60°	IP=25	IP=18	-	-	-	-	-
20 mm TNSh	AP with tungsten carbide core	817	90°	-	-	-	-	-	-	-
23 mm PT-23TB	AP	830	60°	-	-	-	-	-	-	-
23 mm PT-23TB	AP	830	90°	35²	28²	22²	15²	-	-	-
37 mm ZIS-19	AP	915	60°	-	CP=44	CP=38	CP=33	-	-	-
37 mm ZIS-19	AP	915	90°	-	CP=58	CP=50	CP=41	-	-	-
37 mm Modernized "Hochkiss"	AP	442	60°	?	?	?	?	-	-	-
37 mm Modernized "Hochkiss"	AP	442	90°	?	?	?	?	-	-	-
37 mm PS-2	AP	880	60°	-	-	-	-	-	-	-
37 mm PS-2	AP	880	90°	?	?	?	35²	25²	-	-
45 mm 20K, 20Km	BR-240SP	757	60°	-	CP=43	CP=36	CP=31	CP=28	-	-
45 mm 20K, 20Km	BR-240SP	757	90°	-	CP=51	CP=43	CP=38	CP=35	-	-
45 mm VT-42/43	AP	950	60°	-	CP=60	CP=55	CP=51	CP=54	-	-
45 mm VT-42/43	AP	950	90°	-	CP=75	CP=66	CP=59	CP=54	-	-
ZIS-4	BR-271	995	60°	-	-	-	IP=89 CP=83	IP=85 CP=78	IP=79 CP=73	-
ZIS-4	BR-271	995	90°	-	-	-	IP=105 CP=98	IP=98 CP=90	IP=90 CP=82	-
76 mm KT	AP	370	60°	-	-	-	-	-	-	-
76 mm KT	AP	370	90°	?	?	?	31²	28²	-	-
76 mm PS-3	AP	530	60°	-	-	-	-	-	-	-
76 mm PS-3	AP	530	90°	?	?	?	?	?	-	-
76 mm L-10	AP	558	60°	-	-	-	-	-	-	-
76 mm L-10	AP	558	90°	?	?	?	61²	51²	-	-
76 mm F-32	AP	612	60°	-	-	-	-	-	-	-
76 mm F-32	AP	612	90°	?	?	?	60²	52²	-	-
76 mm F-34, ZIS-5	BR-350A	680	60°	-	IP=86 CP=69	IP=79 CP=63	IP=70 CP=59	IP=63 CP=50	IP=52 CP=43	-
	BR-350A		90°	-	IP=89 CP=80	IP=84 CP=76	IP=78 CP=70	IP=73 CP=63	IP=65 CP=58	-
	BR-350B		60°	-	IP=89 CP=74	IP=82 CP=69	IP=76 CP=62	IP=71 CP=55	IP=55 CP=48	-
	BR-350B		90°	-	IP=94 CP=86	IP=90 CP=81	IP=84 CP=75	IP=78 CP=68	IP=69 CP=62	-
	BR-350P		60°	-	CP=92	CP=87	CP=77	n/a	n/a	n/a
	BR-350P		90°	-	CP=102	CP=98	CP=92	n/a	n/a	n/a
85 mm D-5T, S-53, ZIS-S-53	BR-365	792	60°	-	-	-	CP=90	CP=85	CP=78	CP=72
	BR-365		90°	-	-	-	CP=105	CP=100	CP=92	CP=85
	BR-365K		60°	-	-	-	CP=90	CP=78	CP=72	CP=66
	BR-365K		90°	-	-	-	CP=108	CP=102	CP=90	CP=82
	BR-365P		60°	-	-	-	CP=100	CP=85	n/a	n/a
	BR-365P		90°	-	-	-	CP=140	CP=118	n/a	n/a
100 mm D-10T, D-10S	BR-412	880	60°	-	-	-	CP=125	CP=110	CP=95	CP=87
100 mm D-10T, D-10S	BR-412	880	90°	-	-	-	CP=155	CP=135	CP=115	CP=100
107 mm ZIS-6	B-420	830	60°	-	-	-	CP=120	CP=108	CP=92	CP=86
107 mm ZIS-6	B-420	830	90°	-	-	-	CP=140	CP=130	CP=110	CP=95
122 mm D-25T, D-25S	BR-471	780	60°	-	-	-	CP=122	CP=115	CP=107	CP=97
	BR-471	780	90°	-	-	-	CP=152	CP=142	CP=133	CP=122
	BR-471B	780	60°	-	-	-	125²	120²	110²	100²
	BR-471B	780	90°	-	-	-	155²	143²	132²	116²
152 mm S-41	semi-AP round for howitzers	432	60°	-	-	-	CP=71	CP=67	CP=64	CP=60
152 mm S-41	semi-AP round for howitzers	432	90°	-	-	-	CP=87	CP=82	CP=78	CP=73

¹ The Initial Penetration (IP) means the 20% probability of armor penetration. The Certified Penetration (CP) means the 80% probability of armor penetration;
² The tabular data.

III. The ammo types used for the tanks and SP guns

Gun Model	Tanks and SP-Guns	Used Ammo
Gun Model	Tanks and SP-Guns	high explosive	armor-piercing	sub-caliber	shaped-charge	other
45 mm (46 clb) guns
45 mm 20K gun model 1932/38	BT-5, BT-7, BT-7M, T-26 model 1933-1936, T-26 model 1937-1939, T-35	UO-240 UO-240A	UBR-243 UB-241 UB-241M	n/a	n/a	?
57 mm (73 clb) guns
ZIS-2	ZIS-30	UO-271U	UBR-271 UBR-271K UBR-271SP	n/a	n/a	USh-271
ZIS-4, ZIS-4M	T-34-57	the same	the same	n/a	n/a	the same
76.2 mm (16.5 clb) guns
KT	T-26A, BT-7A, T-35, T-28	UO-353A UOF-353 UF-353M	?	n/a	n/a	UD-353A USh-353 USh-353D
76.2 mm (20.5 clb) guns
PS-3	T-28	UO-353A UOF-353 UF-353M	?	n/a	n/a	UD-353A USh-353 USh-353D
76.2 mm (23.7 clb) guns
L-10	T-28, T-35	UO-353A UOF-353 UF-353M	UBR-353A¹	n/a	n/a	UD-353A USh-353 USh-353D
76.2 mm (31.5 clb) guns
L-11	T-34/76 model 1940	UOF-354M UOF-354B UF-354	UBR-354A UBR-354B UBR-354SP	n/a	n/a	UD-354A USh-354 USh-354T USh-354G USh-R2-354
F-32	KV-1 model 1939	the same	the same	n/a	n/a	the same
76.2 mm (41.5 clb) guns
F-34	T-34/76 model 1941, T-34/76 model 1942	the same	the same	UBR-354P	n/a	the same
ZIS-5	KV-1 model 1941, KV-1S model 1942	the same	the same	n/a	n/a	the same
76.2 mm (51 clb) guns
ZIS-3T	SU-76M	UOF-354M UO-354AM UOF-363	UBR-354A UBR-354V UBR-354SP	UBP-354M	n/a	USh-354 USh-354T USh-354G UD-354 UD-354A
85 mm (54 clb) guns
D-5T	KV-85, T-34/85, IS-1	UO-365K	UBR-365 UBR-365K	UBR-365PK³	n/a	?
D-5S	SU-85, SU-85M	the same	the same	UBR-365PK⁴	n/a	?
S-53, ZIS-S-53	T-34/85	the same	the same	UBR-365PK³	n/a	?
122 mm (43 clb) guns
D-25T	IS-2	53-OF-471 projectile with 53-VOF-471 charge	53-BR-471 projectile with 53-VBR-471 charge	n/a	n/a	n/a
D-25S	ISU-122, ISU-122S	the same	the same	n/a	n/a	n/a

¹ In January-February 1941 all these projectiles have been transferred from tanks to regimental field artillery;
² In 1943 this projectile was adding if there was a chance of tank vs tank battle. However, it had poor fuse, so it was quickly removed;
³ Used from summer 1943 only if tank vs tank battle expected. Since 1944 there were 4 rounds in every tank;
⁴ Used from summer 1943 only if antitank mission planned. Since 1944 there were 8 rounds in every SP-gun.

Armor penetration curves of the Soviet and Allied tank guns

2006-01-25T14:52:00Z

(Armor piercing projectiles only; engagement angle 90°)

See the original photocopy of this document

Digital processing: Valeri Potapov
Source: TsNIIP GBTU KA reference, 1944.

Armor Penetration of German Tank Guns

2005-09-23T11:02:07Z

The table below contains data from German sources.

Gun Model	Barrel Length, clb	Ammo	Range, m
Gun Model	Barrel Length, clb	Ammo	100	500	1000	1500	2000
2-cm KwK 30/38	55	Panzergranate 39	20	14	9	-	-
2-cm KwK 30/38	55	Panzergranate 40	49	20	-	-	-
3.7-cm KwK 34(t)	40	Panzergranate 39	37	31	26	22	-
3.7-cm KwK 38(t)	47.8	Panzergranate 39	41	35	29	24	-
3.7-cm KwK 38(t)	47.8	Panzergranate 40	64	34	-	-	-
5-cm KwK 38	42	Panzergranate 39	54	46	36	28	22
5-cm KwK 38	42	Panzergranate 40	96	58	-	-	-
5-cm KwK 39	60	Panzergranate 39	67	57	44	34	26
5-cm KwK 39	60	Panzergranate 40	130	72	38	-	-
7.5-cm KwK 40	43	Panzergranate 39	98	91	82	72	63
7.5-cm KwK 40	43	Panzergranate 40	126	108	87	69	-
7.5-cm KwK 40	48	Panzergranate 39	106	96	85	74	64
7.5-cm KwK 40	48	Panzergranate 40	143	120	97	77	-
7.5-cm KwK 42	70	Panzergranate 39/42	138	124	111	99	89
7.5-cm KwK 42	70	Panzergranate 40/42	194	174	149	127	106
8.8-cm KwK 36	56	Panzergranate 39	120	110	100	91	84
8.8-cm KwK 36	56	Panzergranate 40	171	156	138	123	110
8.8-cm KwK 43/1 and 8.8-cm PaK 43	71	Panzergranate 39	203	185	165	148	132
8.8-cm KwK 43/1 and 8.8-cm PaK 43	71	Panzergranate 40/43	237	217	193	171	153
12.8-cm PaK 44(80)	55	Panzergranate 39	187	166	143	127	117
12.8-cm PaK 44(80)	55	Panzergranate 40/43	193	178	167	157	148
12.8-cm KwK 44	55	Panzergranate 40/43	223	212	200	189	178

US Tank Guns

2005-09-23T10:59:01Z

This table is based upon US sources.

Gun	Calibre, mm	Barrel Length, clb	Ammo type	Projectile weight, kg	Muzzle velocity, m/s	Penetration at 30° at ranges:
Gun	Calibre, mm	Barrel Length, clb	Ammo type	Projectile weight, kg	Muzzle velocity, m/s	500 metres	1000 metres	1500 metres	2000 metres
M6	37	53,5	AP	0,87	885	53	46	40	35
M6	37	53,5	HE	0,73	793	-	-	-	-
M2	75	28	AP	6,79	589	60	55	51	46
M2	75	28	HE	6,67	448	-	-	-	-
M3	75	37,5	AP	6,79	619	66	60	55	50
M3	75	37,5	HE	6.67	464	-	-	-	-
M7	76,2	50	AP	7	793	93	86	82	75
			HVAP	4,27	1037	157	135	116	98
			HE	5,84	854	-	-	-	-
M1	76,2	52	AP	7	793	93	88	82	75
			HVAP	4,27	1037	157	135	118	98
			HE	5,9	854	-	-	-	-
M3	90	50	AP	10,94	808	120	112	104	95
			HVAP	7,63	1022	221	189	176	156
			HE	10,57	823	-	-	-	-
M4	105	22,5	HEAT	13,27	381	102	102	102	102
M4	105	22,5	HE	14,98	473	-	-	-	-

45mm Tank Gun Model 1932/38

2005-09-21T21:33:32Z

Usage:

Production tanks: T-18M, BT-5, BT-7, BT-7M, T-26 Model 1934-1939, T-50, T-70, T-80, T-35, KV-8, KV-8S.
Production armoured cars: BA-3, BA-6, BA-10, BA-11 e` PB-4.
Experimental tanks: A-20, A-32, SMK, T-100, KV-1 Model 1939, KV-4, KV-7-I

At the end of 1931, the designers of Factory No.8 installed a new 45mm barrel on the gun-carriage of the 37mm Anti-tank Gun Model 1930 and slightly strengthened it. The new gun was accepted for service in March 1932, under the designation of "45-mm Anti-tank Gun Model 1932"; the gun's factory designation was - 19K. Afterwards, the designers of Factory No.8 redesigned the 19K field gun to allow a tank installation; it received the designation of "45-mm Tank Gun Model 1932" and, correspondingly, the factory designation of 20K.

Compared to the B-3 gun, the 20K Tank Gun had a number of advantages. The armour penetration of the AP rounds was somewhat improved. The weight of the fragmentation projectile was significantly increased from 0.645 kg to 2.15 kg, and the weight of the explosive charge in this projectile was increased from 22 grams to 118 grams. Lastly, the rate of fire was increased after introducing a vertical wedge semi-automatic breech block, though the refining of the semi-automatic operation took around four years. The first batches of 20K guns were manufactured with the 1/4 automatic operation. Later versions were fitted with semi-automatic operation for armour-piercing rounds and 1/2 automatic operation for high explosive fragmentation rounds. The first deliveries of the guns with the properly refined semi-automatic operation for all the kinds of ammunition began in 1935. The 20K gun had a disadvantage: it did not fit into the small turrets of the T-26 and BT-2. Theoretically, it could be "crammed" into the turret, but that required the introduction of a balancing mechanism, a new elevation mechanism, and thus left only enough room for one crewmember. There was no space for a second crewmember. The RKKA High Command did not approve of this, and the T-26 and BT tanks begun to be manufactured with a new large turret - correspondingly the single turret T-26. This version of the T-26 tank with the 45-mm Tank Gun Model 1932 was delivered to NIAP on 31 May 1933.

Since 1932, the 20K gun had been in production at Factory No.8. Ten guns were produced in 1932; 2099 in 1933; 2005 in 1934; 2443 in 1935 and so on. Altogether, 21564 20K guns had been produced by January 1, 1941.

Factory No.8 received an order to produce 2664 45mm 20K Tank Guns in 1941. There were no plans to cancel production of the 20K in the near future, because they were to become the armament for the new main tank (T-50 or T-126SP). Actually, 2759 guns were produced in 1941.

Since 1942, production of the 20K was transferred to Factory No.235 where 5090 guns were manufactured in 1942, and 3040 were produced in 1943. Production of the 20K was then finally stopped. From the beginning of the 1930's to mid-1943, a 45mm gun system remained practically the only anti-tank gun. This was a result of these guns being able to penetrate the armour of any German tank, prior to 1942, from up to 500 metres. Theoretically, they were superior to the German 37mm Pak 36, as they had a more effective HE capability. However, on practice it was doubful due to some flaws with AP ammunition issued in 1941; firing tests indicated certified penetration was about 18-20mm at 500 metres while all sources of that time claimed 35-40mm. Flaws occured due to over-heat the AP projectle so it's nose tended to brake up in piecese during impact.

The 20K had undergone several modifications. For instance, the Model 1934 gun differed from the standard prototype (Model 1932) in design of the semi-automatic mechanism, recoil systems, elevation mechanism etc. The Model 1938 gun featured the introduction of an electric firing mechanism. Our website lists all these artillery systems under the common designation of "45mm Tank Gun Mod.1932/38", to avoid repeating insignificant details.

In 1938, the TOS gun-sight with stabilisation of the line of fire in the vertical plane was developed for the 45mm Gun Mod.1938 with the electric firing mechanism. Stabilisation was achieved by way of a gyroscope hung in the front section of the sight's housing. Some T-26 and BT-7 tanks were equipped with the TOS, but this system was taken out of service at the beginning of the war. This was done because it was not properly mastered by combat units; and also due to some shortcomings in design and operational service for which there was no time to address in that difficult period.

Several years before, in 1936, an experimental prototype of the automatic loading mechanism for 45mm tank guns was designed by engineer Rozhdestvenskiy. It was manufactured at the Military Electro-technical Academy of RKKA. Factory No.8 was assigned to refine this mechanism and start its mass production, although it had not begun this assignment after two years, and later it rejected the assignment altogether.

In 1938, the 45mm Automatic Tank Gun VETOG, with an automatic belt fed ammunition mechanism patterned after the 37mm Maxim Gun, was created in NITI on the basis of the 20K. In the same year, the Artillery Directorate decided to cancel all work on the "VETOG" gun for the following reasons:

"Factory No.8 works on 45mm and 37mm automatic guns. Only the one that is finished earlier will be recommended for use in teletanks (remotely controlled tanks)"

The work to create the 45mm armour-piercing chemical (APCh) projectiles for the 19K (field) and 20K (tank) guns is also quite interesting. Such a projectile would explode behind the tank's armour (i.e. inside the fighting compartment) and would produce poison gas to kill the crew. In 1934, the trials of the 45mm APCh projectile by "Blueprint No.180" were commenced in NIAP. Unfortunately, the trials results still remain top secret to this day.

20K GUN SPECIFICATION
Parameter	Value
Calibre, mm	45
Bore lenght, clb	46
Weight of pendulous elements, kg	313
Weight of recoil elements, kg	113
Normal recoil length, mm	240-270
Max recoil length, mm	278
Max range, m	~4200
Ammunition	fixed
Ballistic	45mm anti-tank gun mod.1932
Practical ROF, shot/min	7-12

ARMOR PENETRATION TABLE
Projectile	V, m/s	Engagement angle, degrees	Range, m
Projectile	V, m/s	Engagement angle, degrees	100	300	500	1.000
BR-240SP	757	60°	43	36	31	28
BR-240SP	757	90°	51	43	38	35

AMMUNITION FOR THE 20K GUN
SHELL		PROJECTILE					PROPELLANT CHARGE
Index	Weight, kg	Index	Weight, kg	Length, clb	Weight of a charge, gram	Fuse	Index	Weight, kg
HIGH EXPLOSIVE, FRAGMENTATION
UO-240	2.91	O-240	1.98 2.14 2.15	4.6 4.6 4.6	135 118 118	M-50 KTM-1 KT-1	?	0.1 or 0.115
UO-240A	2.91	O-240A³	1.98 2.14 2.15	4.6 4.6 4.6	135 118 118	M-50 KTM-1 KT-1	?	0.1 or 0.115
ARMOR PIERCING
UBR-243	2.45	BR-240	1.43	3.8	18.8	MD-5	?	0.36
UBZR-243	2.45	BRZ-240	1.43	3.8	12.5	MD-5	?	0.36
UBR-243SP	2.45	BR-240SP	1.43	3.8	N/A	N/A	?	0.36
UB-241	2.44	B-242	1.35	4.3	58	MD-2	?	0.1
UB-241M	2.44	B-241*	1.41	3.6	77	MD-2	?	0.1
ARMOR PIERCING SUB-CALIBER
UBR-243P	1.84	BR-240P**	0.85	2.7	N/A	N/A	?	0.365 or 0.38
CANISTER AND SHRAPNEL
UShe-243	2.36	She-240***	1.62	5.4	N/A	N/A	?	0.1
INCENDIARY
n/a
SMOKE
n/a

* Turned from 47 mm Hochkiss naval round;
** Developed and accepted for service on 1.04.42;
*** Canister with 137 bullets of total weight of 1,48 kg

Translation: Rodion Podorozhny
Proof-read: Chris Amundson
Sources: "Artillerijskoye Vooruzhevie Sovetskikh Tankov 1940-1945" Armada-Vertical, No.4, 1999
A.Shirokorad "Entsiklopediya Otechestvennoi Artillerii", 2000
M.Svirin, A.Beskurnikov "Pervie Sovetskie Tanki", Armada No.1