Penetration

Penetration (or, rather, overpenetration) is an important topic for small arms as well as artillery. In this document, several different pistol rounds are compared in their ability to punch through 11 dry pine boards from a distance of 25 meters.

The guns in the list are:

• "Mod. 1930" (likely TT-30)
• Voyevodin's design
• Browning (likely Hi-Power)
• Lakhti-35
• Star 7.63 mm
• Borchardt-Luger
• Colt M1
• Mauser 7.65 mm
• Sauer

The note on the bottom says that the Star pistol was using 7.62 mm model 1930 cartridges, more commonly known as 7.62 Tokarev. As you can see, that particular pistol was the most impressive, penetrating 8 boards with 10/10 shots, and the only gun to make a hole in the 10th and 11th board. The TT-30 doesn't do as well, only conquering 6 boards, but that's still better than the .45 bullet of the 1911 (3 boards) and 9 mm Luger (4 boards).

Via kris_reid

PTRD vs PTRS

"Evaluation of Degryaryev and Simonov anti-tank rifles based on the reviews of privates, Sergeants, and officers of anti-tank rifle units

1. Simonov's rifle starts jamming after only a small amount of fouling in the chamber, after 10-15 shots. Degtyaryev's rifle is flawless in its action. I knocked out a tank near Skopishki at 300 meters (with a BO-32 bullet). - Sergeant Pazharduk, 665th Reg., 216 Div.
2. The Degtyaryev anti-tank rifle has an insufficient rate of fire for fighting tanks, reloading takes too long. The rate of fire of Simonov's rifle is good, but heavy for attacking. Their weakness is that they are not used with the whole unit, but split up among companies and platoons, which removes the ability to fire in groups on tanks and other targets. BO-32 bullets have weak incendiary properties, BO-41 bullets are good. - Sergeant Pikalov, 346th. Div.
3. The PTRD is an excellent weapon, works flawlessly. The PTRS jams often when there is any dirt in it or when the lubricant freezes. - Artillery Quartermaster, 1166th Reg., 346th Div. Jr. Military Technician Prikhodko
4. The PTRD is flawless in battle, never has any jams that create difficulties on the battlefield. However, its weakness is that it has no magazine. The PTRS has a high rate of fire, and is convenient to carry, as it can be taken apart and put back together quickly. Its drawback is that it has many jams that cannot be fixed on the battlefield, the assembled rifle is heavy, the round casings burst often, and the chamber is fouled, which results in jams. 4 medium tanks were knocked out with anti-tank rifles from 300 meters (BO-41 bullet), and three armoured cars from 200 meters. - Artillery Quartermaster, 1168th Reg. 346th Div.
5. The PTRS has sufficient rate of fire, and sufficient penetration for a light or medium tank. Its drawbacks include jamming in dusty conditions and case expansion, which makes reloading difficult.
   The PTRD is light and mobile, reliable in cold and dust. The penetration is sufficient. Drawbacks include a lot rate of fire. During fighting in Lithuania and Latvia 3 tanks were knocked out at a range of 250-300 meters with incendiary bullets. - Commander, 1st Company, 1168th Reg. 346th Div. Captain Gotozhkov
6. The PTRD is superior to the PTRS, its penetration is good. With three aimed shots, an enemy machinegun was destroyed at 250 meters. Company commander, 346th Div. Sr. Lieutenant Deritz
7. The anti-tank rifle is a good weapon for destroying enemy strongholds, armoured cars, and other weapons. - Sr. Sergeant Fedoseev
8. The penetration of the anti-tank rifle at 100 meters is 45 mm. The rate of fire of the PTRS is 10-15 RPM, of the PTRD is 8-10 RPM. The rate of fire is good. The anti-tank rifle is very effective at destroying enemy machinegun nests. The anti-tank rifle likes cleanliness, good care, and constant lubrication. - Jr. Sergeant Kvichko
9. Anti-tank rifle units prefer to be armed with PTRD rifles, as they are lighter and more reliable. Currently, AT rifles are rarely used against tanks, as our units are saturated with AT artillery. They are normally used to destroy cars, prime movers, and light armoured cars. - Artillery Quartermaster, 417th Div. Malinin

Conclusions

1. In the second phase of the Patriotic War, when the Red Army went on the offensive on all fronts, our forces became saturated with AT artillery, improvement of armour on medium tanks and increased numbers of heavy tanks, the importance of anti-tank rifles as anti-tank weapons decreased drastically.
   The anti-tank rifle lost its power as an infantry anti-tank weapon. Artillery effectively fights tanks now. The anti-tank rifle, due to its high precision, is now used against open enemy concentrations, armoured cars, and APCs. This is natural, given the state of equipment of infantry at this time.
2. Almost all anti-tank rifle units speak well of the PTRD: light to carry and flawless in battle. Some wish to increase its rate of fire, others mention that the rate of fire is the only good quality of the PTRS. There are no positive reviews of its reliability, only negative. After 10-15 shots, it starts jamming, and these jams are hard to fix, consume a lot of time, which is unacceptable in modern fast-paced battle.
   The PTRS is unusable in battle, and its subsequent production is pointless.
3. Retain the PTRD in production, increase its rate of fire.

51st Army HQ Chief, Major-General Dashevskiy

Chief of the Artillery HQ, Colonel Shvedkov

September 28th, 1944"

Via artem-mr.

MKb 42(H) First Appearance

I wrote about Sturmgewehr intel before, but here's an even earlier appearance:

"Main data:

1. Automatic fire provided by gunpowder gases passing through the gas opening.
2. The barrel locks via the bolt tilting.
3. Uses a special shortened round, similar to the rifle ones.
4. Range: up to 800 meters.
5. Has a selector for automatic and single-shot fire.
6. Equipped with a bayonet for hand to hand combat."

The intelligence brief reads:

"Carbine-machinegun MK-42

The model 1942 7.92 mm carbine-machinegun with a 30-36 round special magazine (uses shortened 7.92 mm rifle bullets) is carried on a strap affixed to the stock and across from the bayonet lug. It's easy to disassemble. Judging by the design, the magazine is also used as a foregrip (there is no sign of an attachable bipod). Externally, the gun is composed of the following parts:

1. Barrel
2. Front sight with safety
3. Gas piston pipe
4. Barrel shroud
5. Rear sight
6. Bolt
7. Magazine
8. Base with pistol grip and trigger guard
9. Stock with an opening for accessories

The striker mechanism of the machinegun-carbine is composed of the following parts:

1. Gas piston
2. Operating slide
3. Bolt base
4. Bolt (there is a safety on the bolt plunger and a handle for pulling it back)

The bolt is composed of the following parts:

1. Bolt case
2. Extractor
3. Firing pin

Judging by the design of the cooling system, it can be expected that the rate of fire and automatic qualities of the machinegun-carbine are not high."

PTRS Penetration

"August 25th, 1941
To the Chair of the State Committee of Defense of the USSR, comrade Stalin I.V.

Engineer Simonov proposed an anti-tank rifle that is both simply designed and powerful. During trials at NIPSVO, the following characteristics were recorded:

• Caliber: 14.5 mm
• Mass: 21.45 kg
• Length: 2220 mm
• Muzzle velocity: 1060 m/s
• Practical rate of fire: 15 RPM

The penetration of this rifle is sufficient to fight enemy light and medium tanks, as demonstrated in the following tables:

Range (meters)	Angle (degrees)	Armour thickness (mm)	Percentage of complete penetrations
Production bullet
350	20	20	80%
Metallo-ceramic bullet
100	0	40	100%
200	0	35	100%
300	0	35	100%
700	0	30	100%
700	20	20	100%
1000	20	20	100%
1200	20	20	50%
Metallo-ceramic bullet with tracer
100	0	50	100%
150	0	50	50%
250	0	40	50%
200	20	35	100%
250	20	35	100%
700	20	30	100%
800	20	30	50%

The German anti-tank rifle is a good mass produced measure against light tanks at ranges of up to 500 meters. Simonov's rifle, on the other hand, has superior power, rate of fire, is simpler to produce, and allows infantry to independently fight tanks at the following ranges:

• 20 mm: 1000-1200 meters
• 30 mm: 700-800 meters
• 40 mm: 200-250 meters
• 50 mm: 100-150 meters

Additionally, Simonov's rifle is self-loading, allowing firing of 5 shots in 4-5 seconds in close range tank attacks. 

I think that is is necessary to take action to put Simonov's 14.5 mm anti-tank rifle into production.

Chief of the Red Army GAU, General-Colonel of Artillery, Yakovlev

Red Army GAU Military Commissar, Brigadier Commissar, Novikov"

Via gistory.

PzB 39 Evaluation

"To the Chair of the State Committee of Defense, comrade I. Stalin

Trials of the German PzB 39 7.92 mm rifle by the Red Army Small Arms Scientific Research Proving Grounds showed the following results:

1. Muzzle velocity: 1189 m/s
2. Mass: 12.12 kg
3. Bullet mass: 14.8 grams
4. Chamber volume: 17.06 cm^3

The rifle penetrates a 20 mm surface hardened plate at a 20 degree angle from 500 meters and a 30 mm surface hardened plate at a 20 degree angle from 300 meters. Further trials were not performed as only 7 rounds were available for testing.

The PzB 39 7.92 mm rifle can be considered an effective weapon against 20 mm armour at 500 meters and 30 mm armour at 300 meters. Considering the army's need of anti-tank rifles, we consider it necessary to produce at least 30,000 rifles similar to the German one annually. As it is not possible to solve this problem using the resources of the People's Commissariat of Armament without reducing production of other weapons, we ask that the "Avtotraktordetal" factory in Saratov be transferred to the NKV.

People's Commissar of Armament, D. Ustinov."

The One with the Rifle Shoots

Somehow, the scene from Enemy at the Gates is considered real by some people, but the situation in real life was rather different. Even in blockaded Sevastopol, nobody sent soldiers to the front lines with no rifles.

"Order #03 for the second defense sector, November 19th, 1941

1. By order of the commander of the 31st Infantry Regiment, 43 rifles were confiscated from rear servicemen of the regiment. 43 soldiers were armed and sent to the front.

I approve of the initiative of the commander of the 31st regiment and order that:

1. Immediately take inventory of all weapons in the rear forces, leave 1-2 rifles per squad and send the rest to arm the front line troops.
2. The commandant of the sector HQ must confiscate weapons from rear servicemen, political department, operations department, prosecution, and tribunal.
3. Immediately confiscate all submachineguns from HQs, regimental and divisional rear servicemen, political department, operations department, prosecution, tribunal, medical units and drivers, send them to:
1. Regiments: to front line companies and reconnaissance units.
2. Divisions; to the chief of artillery armament, comrade Oskin.
4. I must ask commanders and commissars to pay attention to some soldiers that, when the enemy pressures them, retreat and throw down their rifles and even machineguns.
   I demand the strictest responsibility of soldiers and commanders for the weapons given to them. Those that abandon their weapons will be brought before a military tribunal. Form small squads headed by a brave unit commander to retrieve weapons from the dead and heavily wounded in each company. Each rifle and especially machinegun must be saved no matter what."

Via gistory.

Wonder Bullet

"Act

On July 6th, 1941, based on the orders of the OTB chief, Major of State Security comrade Kravchenko and GAU KA chief, Colonel-General comrade Yakovlev we, [long list of commission members] performed trials of 7.62 mm AP-I bullets with a ceramic-metallic core and gunpowder developed by the OTB NKVD at the OTB NKVD proving grounds to establish their effectiveness.

Experimental rounds of two types were submitted for trials. One type had 4.15 grams of propellant, the other 4.2 grams. Characteristics of the rounds are shown in attachment #3.

Trials were performed against 20 mm surface hardened armour (see characteristics in attachment #1) with the air temperature of 28-29 degrees and range of 100 and 150 meters.

The following bullets were used to test the quality of the armour plate and compare the effectiveness of experimental bullets:

1. Stock rounds with B-32 bullets.
2. Rounds with 3.15 grams of propellant and a metallic-ceramic core.
3. Rounds with 4.2 grams of experimental gunpowder and B-32 bullets.

These bullets were fired at 50 meters, as firing them from larger ranges made no sense due to their ineffectiveness against 20 mm of surface hardened armour from even 50 meters. Results are contained in the following table:

	Hits	Complete penetrations	Incomplete penetrations	Complete penetrations, part of bullet is stuck	% penetrations
Stock round with B-32 bullet	5	0	51		0
Experimental round with B-32 bullet	5	0	51		0
Experimental round with metallic-ceramic bullet (w=3.15)	5	0	52		0
Experimental round with metallic-ceramic bullet (w=4.15)	5	3		2	100
	21	3	13	21	95.2
Experimental round with metallic-ceramic bullet (w=4.2)	5	3		2	100

Notes:

1. Dents on one side, no effect on the other side.
2. Three hits caused bulges on the rear side, two had the bullet tip penetrate completely.
3. The bullet tip penetrated completely.

In order to test the incendiary action of the bullets, experimental rounds (w=4.2) were fired from a range of 150 meters at a 20 mm plate with a full gasoline tank up against it. As a result, the gasoline ignited from the first shot that hit the gasoline (the first shot that was fired hit above the gasoline). Both bullets penetrated the armour completely.

Conclusions

1. The effectiveness of the experimental OTB NKVD rounds is superior to all currently known 7.62 mm armour piercing incendiary bullets.
2. The results should be immediately checked at NIPSVO to establish ballistic norms and more carefully establish the armour penetration effectiveness. For this purpose, USV GAU should produce 500 bullets with ceramic-metallic cores by July 6th, 1941, and OTB NKVD must assemble them and send them to NIPSVO by July 7th, 1941.
3. Due to good results of trials, do not wait for NIPSVO trials to complete and begin production with existing propellant. USV GAU must provide the bullets for this batch. The batch must be complete by July 15th, 1941.
4. NKO must give the order to NKB for production of the gunpowder developed by the OTB NKVD at factory #40 in the amount of 7-10 tons, and NKV must set up production of 7.62 mm bullets with ceramic-metallic cores at factory #188.
5. Calculate the propellant load with the aim to produce average pressure less than 3200 kg/cm^2 as both rounds tested had similar results."

RGASPI 664-1-1

AK Muzzle Devices

The accuracy of an automatic weapon is important, and many experiments were run on the AK platform to figure out if it can be increased. A number of experimental muzzle devices were built for this purpose. _tezka provided this picture.

Left to right: similar to stock type, brake-compensator, two chamber, flash suppressor, single chamber, reactive.

While all of these successfully reduced muzzle climb and improved accuracy, there was one important drawback that engineers did not necessarily consider...

"The positive effect of the muzzle brake on the accuracy is at odds with the negative result of the sound wave hearing, which is greatly increased to unacceptable levels with most muzzle brakes.

...

The evaluation of the effect of the sound waves on hearing reveals that all muzzle brakes in the table result in a bothersome or painful sensation in the ears."

A DShK style reflector was considered to remedy this effect, but...

"...a reflector of such size can hardly be recommended as they decrease the maneuverability and comfort of the weapon and do not achieve the intended result of reducing the sound to a level that does not cause pain."

Another device was tested to improve accuracy, but it was a different kind of brake.

Curiously enough, it was a brake for the bolt. The experiment was meant to determine the effect of the speed of the bolt flying back and forth on accuracy. The knobs on the sides could adjust the force applied to the bolt in order to slow it down.