US Bazooka M6A3 Rocket

[hchris]

Hello everybody,

I am currently trying to find a definitive evidence of how much armor the US Bazooka M6A3 round penetrated?

I am looking for something official, a manual, penetration tests, whatever. Something which is really reliable.

Does anybody have anything?

[Saxon Cross]

Hello everybody,

I am currently trying to find a definitive evidence of how much armor the US Bazooka M6A3 round penetrated?

I am looking for something official, a manual, penetration tests, whatever. Something which is really reliable.

Does anybody have anything?

Hi,

I doubt you will find the iron clad answer you are looking for.

The manual for the M6A1 is non-commital and just says:

24. EFFECT.

a. ROCKET, H.E., A.T., 2.36", M6A1, has effect against various targets as follows:

(1) ARMOR PLATE. Penetration of armor found on most tanks may be expected at all ranges. A hole is blown through the armor and heated particles of metal are sprayed through in a cone shaped pattern. Any ammunition within this pattern is usually exploded.

(2) MASONRY. Penetration of brick and masonry from several inches to a foot or more, depending on quality of structure, may be expected.

(3) STRUCTURAL STEEL. Produces shattering effect against cast steels and such materials as girders and railroad rails. Produces extensive damage, probably irreparable, to motor blocks.

(4) WOOD. Penetration of timber from several inches to a foot or more, depending on the timber, may be expected.

http://www.lonesentry.com/manuals/bazoo ... -m6a1.html


The Bazooka penetration is most often cited at 75mm - 126mm.

One of the reasons for the large range of reported penetration may be that most sources don’t discriminate between the various WW2 rockets, and then the type and quality of the armour is always a variable and can make a large difference; and the angle of attack (zero/90 degrees, 30 deg. 45 deg. 60 deg.) will also make a substantial difference to penetration results.

After a lot of research (for my own project) looking at numerous published sources, I would roughly say the following was about right:

At a 30deg slope/angle which is the standard for pen results:

M1 Bazooka with M6 rocket (75-80mm pen)
M1A1 Bazooka with M6A1 rocket (around 100mm pen?)
M9 Bazooka with M6A3 rocket (120-126mm pen)

The M6A1 was the hardest to find solid sources for.

DATES

First Adopted:
M1 Bazooka with M6 rocket (Jul 1942)
M1A1 Bazooka with M6A1 rocket (Jul 1943)
M9 Bazooka with M6A3 rocket (Oct 1943)

In front line troops hands:
M1 Bazooka with M6 rocket (Nov 1942)
M1A1 Bazooka with M6A1 rocket (Oct 1943)
M9 Bazooka with M6A3 rocket (Jan-Feb 1944)

Sources include but not limited to:

1. Forty, 1979
"U.S. Army Handbook" (first edition), George Forty, Ian Allan, 1979, pages 99 and 107. Ammunition and armour type unspecified,
M1 and M9: 119mm at 90deg

2. Isby, 1974
"Patrol! Modern Infantry Tactics, 1914–74", David C. Isby, in: Strategy & Tactics No. 46, Simulations Publications, Inc., Sept/Oct 1974, page 35. Armour type and slope not specified,
M9 2.36" Bazooka: 100mm


3. Here’s a quote from Hogg's "Tank Killing":

The 2.36inch Launcher M1/M9 used the M6 series bomb.
Rockets were interchangeable between M1 and M9 launchers.

M6 rocket pen approx 80mm (early prod)
M6A1/A2 rocket pen approx 100mm (mainly M1 Bazooka)
M6A3/A4 rocket pen approx 120mm (mainly M9 Bazooka)
M6A5 rocket approx 125mm (post war)

4. This site:
http://www.inert-ord.net/atrkts/bazoo/
has the rockets like this:

M1 uses M6 (80mm pen)
M1A1 uses M6A1
M9 uses M6A3 (126mm pen)

---
There's anecdotal evidence that the Bazooka had a harder time with heavy German tanks than the PIAT, but I find that difficult to believe once the M6A3 rocket was introduced.

Here’s some interesting data that people often overlook:

Rocket velocity:

Bazooka: 270 fps
Panzershreck: 345fps
PIAT: 450fps

The Panzerfaust varied depending on the version:
30:98fps
60:150fps
100:200fps
150:280fps

regards,
Saxon Cross

[hchris]

First off all, thanks a lot for your time.


I have been researching the bazooka for a few months now but didn't have a lot of luck with reliable sources concerning the penetration capabilities although I have some declassified US army and armanent department documents. Sadly they all lack a penetration number.

I only found in an early FM23-30 that the Bazooka firing the M6A1 could penetrate 3" of armored steel plate @ 90°.

Honestly I doubt that the penetration really varied a lot between the different M6 variants as they all used the same amount and type of explosive, the hollow charge cone had the same design, only the fuze arc was changed when the nose was adjusted from conical to rounded. So I cannot really find a reason why the penetration should improve significantly.

I did hear rumors that the cone material was changed from ferrite steel to copper, but as I said, only rumors, no proof or anything so far. It was claimed that this helped to improve the penetration, but without an evidence it stays what it is, a rumor.

[Saxon Cross]

I only found in an early FM23-30 that the Bazooka firing the M6A1 could penetrate 3" of armored steel plate @ 90°.

Honestly I doubt that the penetration really varied a lot between the different M6 variants as they all used the same amount and type of explosive, the hollow charge cone had the same design, only the fuze arc was changed when the nose was adjusted from conical to rounded. So I cannot really find a reason why the penetration should improve significantly.

I did hear rumors that the cone material was changed from ferrite steel to copper, but as I said, only rumors, no proof or anything so far. It was claimed that this helped to improve the penetration, but without an evidence it stays what it is, a rumor.

I have heard about the copper from several sources, and I think some were quite solid. I apologise that my info. isn't better sourced. I have it all written down somewhere

Here's one of the copper rumours:

While the Bazooka’s M6A1 and M6A2 rockets initially used mild steel cones, sometime after July 1943, the M6A3 rocket was introduced. The M6A3 used a copper cone. Conversely, all Marks of the PIAT bomb used mild steel cones. Again, if one were to hold all else constant, a copper cone will out-perforate a mild steel cone by about 25% to 40% -- depending upon the cone angle.
http://208.84.116.223/forums/index.php?showtopic=22116

Here's another copper source:
http://www.inert-ord.net/atrkts/bazoo/

Here's a source that says:

The M6A1 can penetrate three inches of homogeneous steel
armor plate at angles of impact as low as 30 degrees.

It goes on to say:
The 2.36 inch A/T Rockets M6A1 and M6A3 are identical except for difference in the
ogive and the tail assembly. In other respects the two rockets are similar, consisting of a
hollow ogive crimped onto the body, a body union fitting into the base of the body with
internal threads to receive the motor, and a fuze which is located in the forward end of the
motor tube. The M6A1 has a conical ogive, whereas the M6A3 has a hemispherical ogive
which gives better penetration by forming a stronger stand-off piece for the shaped-
charge effect of the explosive.

http://www.saw.usace.army.mil/campbutner/AppendixE.pdf

So that source doesn't mention 'copper', but says the M6A3 has better 'stand-off' and therefore better penetration.

I will see if I can dig up something more official.

Saxon Cross

[Saxon Cross]

I now have a 1944 declassified US War Department document, from the Ordnance School, Aberdeen Proving Grounds, that describes the M6A1 and M6A3 in detail.

1. The M6A1 can penetrate 3 inches (76mm) of armor at 30deg.

2. The M6A3 penetration is said to be "uniformly improved", but it doesn't provide a depth.

The reasons for improvement are entirely down to the change in the nose (ogive) shape.

There's absolutely no mention of "copper" in the whole document, and in fact the document lists every change to the M6A3 rocket over the M6A1:

(a) Nose (ogive) shape from pointed conical to rounded hemisphere.
This is the most important change, resulting in:
*better chance of detonation
*faster detonation which results in better stand-off and better penetration.

(b) Improved tail assembly.
Slightly better ballistic qualities

The document says there were no other changes, to the M6A3 and it is similar to the M6A1 in all other respects.

It seems the copper cone is a rumour, just like you said.
Perhaps a post war rocket used copper and someone got confused?

There's a lot of disinformation out there!

I'll PM you, and get the document over to you.

regards,
Saxon Cross

[LWD]

Better machining of the components can also increase the penetration of a hollow charge. As mentioned "stand off" is also important as there it takes a certain amount of time for the "jet" to form for maximum penetration and this wasn't well understood at the time. A faster fuse or a change in the distance from the fuse to the charge could have considerable increase on the effect. If the tests were done at greater ranges this could have a similar effect as the rocket would be traveling slower at longer range in effect giving it greater stand off. There is a fair amount of info available on the net on the theory and practice of shaped charges. Not sure how good much of it is however as I suspect a fair amount is classified.

[Saxon Cross]

I've found an 'official' penetration for the M6A3.

According to test data from 1943 to 1953 the M6A3 could penetrate approx. 3.5 to 4 inches (89 to 102mm ) of hardened armor plate.

It's from a 2002 Ordnance and Explosives (OE) Removal Action document

Eastern Bypass
Amendment 1
Fort McClellan, Alabama
Delivery Order 0010
Contract Number DACA87-99-D-0010

I can see the document, but cannot download a PDF.
The relevent part says:

22 August 2002

SUBJECT: Documentation of 2.36-inch H.E.A.T. Rocket (M6A3) Stand-off Distance
for Mechanical Removal Using T-1 Armor, 9/16-inch Thickness

1. Reference historical test data from various developmental tests of 2.36-inch HEAT
rockets, obtained from Redstone Scientific Information Center, 1 August and 22 August
2002. Also, personal consultations with Dr. David Lydell, Jet Research Center,
Halliburton, Inc. were conducted on 8 and 22 August 2002.

2. Characteristic and test data for the 2.36-inch HEAT round were obtained from file
documents dated 1943-1944, 1952, and 1953. Additional detailed schematics of the
rocket and components were reviewed from ordnance manuals. The HEAT round is
composed of a shape charge with the following characteristics: explosive filler – 0.5
pounds of Pentolite, steel cone of 78.7 grams weight, 48 mm diameter at open end, 68
mm in length and a 2.5 mm wall thickness. The nose cone standoff distance to the shape
charge is approximately 4 inches. Expected penetration of the shape charge is
approximately 3.5 to 4 inches of hardened armor plate.

3. Approximately 95% to 97% of the ordnance used at this site was training rounds (M7
A2/A3). However, the potential detonation of a HEAT round during mechanical
excavation and power screen processing poses a problem for protecting the equipment
operators. No test data was found which could substantiate the effective distance of the
“jet/slug” from the HEAT warhead with respect to detonation in a manner different from
intended use. That is, if the round detonated in free space and not at its optimum stand-
off distance for maximum armor penetration, at what distance could it penetrate the 9/16-
inch T 1 armor proposed to be used on the equipment?

4. Jet Research Center, a division of Halliburton, Inc., specializes in developing and
testing jet penetrators (shape charges) for use in oil well development and demolition
munitions. Dr, David Lydell is a specialist in shape charge design, having worked for the
U. S. Government in warhead development and design. Given the particular
characteristics of the 2.36-inch HEAT round he was able to model the effective standoff
distance for the proposed T 1 Armor. The modeling indicates that the jet/slug will not
penetrate the T 1 (9/16-inch) at a distance of about 13 feet. That is, the jet/slug is a
ballistic fragment without the capability to burn through the armor.

5. Historical records indicate that improvements in shape charge warhead design for the
2.36-inch HEAT round were conducted from 1946 through 1953. An improved round
(M6A5) was tested in the 1952 –1953 timeframe. The shape charge was changed to
include 0.97 pounds of Composition B explosive as a replacement for the Pentolite. This
extended the length of the warhead to the rear to accommodate the added explosives. All
other characteristic components appear to have remained the same. Extensive design and
development was completed on the nose cone and the shape itself since the proper
functioning of these two components control the capability to develop optimum
penetration of the warhead. A second round of modeling by Dr. Lydell indicates that the
added explosive has little effect on the 13-foot standoff distance for the equipment armor.
Most of the added explosive force resulted in more fragmentation effects for the round.

6. A records search of the Ft. McClellan Archives Search Report was conducted to
determine when the 2.36-inch rocket range was used and abandoned. Based on those
records, the range was active during and shortly after World War II. In 1947, Ft.
McClellan was inactivated. Ft. McClellan was re-activated in the 1951-1952 timeframe.
Troop training in use of anti-armor ordnance was not part of the next few years’ activity.
The records indicate that the 2.36-inch range was probably closed in the early 1950’s.
Therefore, the most likely scenario for the 2.36-inch rocket range is that the M6A3 will
be HEAT round used at the site for 2.36-inch rocket training.

Porter Morgan
Technical Manager
OE Removal Projects
Fort McClellan, AL
CEHNC-ED-CS-G

---

You can see the document here (but you may have to use the 'quick view' as PDF download was not working for me):

http://www.google.com/search?q=Part05_A ... tartPage=1

or try this:

http://docs.google.com/viewer?a=v&q=cac ... mEFtkU0oKA


Saxon Cross

[hchris]

I now have a 1944 declassified US War Department document, from the Ordnance School, Aberdeen Proving Grounds, that describes the M6A1 and M6A3 in detail.

1. The M6A1 can penetrate 3 inches (76mm) of armor at 30deg.

2. The M6A3 penetration is said to be "uniformly improved", but it doesn't provide a depth.

The reasons for improvement are entirely down to the change in the nose (ogive) shape.

There's absolutely no mention of "copper" in the whole document, and in fact the document lists every change to the M6A3 rocket over the M6A1:

(a) Nose (ogive) shape from pointed conical to rounded hemisphere.
This is the most important change, resulting in:
*better chance of detonation
*faster detonation which results in better stand-off and better penetration.

(b) Improved tail assembly.
Slightly better ballistic qualities

The document says there were no other changes, to the M6A3 and it is similar to the M6A1 in all other respects.

It seems the copper cone is a rumour, just like you said.
Perhaps a post war rocket used copper and someone got confused?

There's a lot of disinformation out there!

I'll PM you, and get the document over to you.

regards,
Saxon Cross

As long as I don't see any official documents which mention the copper cone, I will stay with it being a rumor.

There were nations who used copper for their cones as far as I can remember, but I am not 100% positive they were deployed in WW2. Most of the post war HEAT shaped charges used copper if I remember correctly.


I rechecked the document you sent me, I already went through it a few weeks ago, but I cannot remember that it lists the penetration of the M6A1 @30°? As far as I remember it says 3", but no deg are listed, which usually it means if the rocket strikes the armored plate at an right angle (90°).

As far as I remember it says the maximum fuze arc is 30°, doesn't it?

[hchris]

I've found an 'official' penetration for the M6A3.

According to test data from 1943 to 1953 the M6A3 could penetrate approx. 3.5 to 4 inches (89 to 102mm ) of hardened armor plate.

It's from a 2002 Ordnance and Explosives (OE) Removal Action document

Eastern Bypass
Amendment 1
Fort McClellan, Alabama
Delivery Order 0010
Contract Number DACA87-99-D-0010

I can see the document, but cannot download a PDF.
The relevent part says:

22 August 2002

SUBJECT: Documentation of 2.36-inch H.E.A.T. Rocket (M6A3) Stand-off Distance
for Mechanical Removal Using T-1 Armor, 9/16-inch Thickness

1. Reference historical test data from various developmental tests of 2.36-inch HEAT
rockets, obtained from Redstone Scientific Information Center, 1 August and 22 August
2002. Also, personal consultations with Dr. David Lydell, Jet Research Center,
Halliburton, Inc. were conducted on 8 and 22 August 2002.

2. Characteristic and test data for the 2.36-inch HEAT round were obtained from file
documents dated 1943-1944, 1952, and 1953. Additional detailed schematics of the
rocket and components were reviewed from ordnance manuals. The HEAT round is
composed of a shape charge with the following characteristics: explosive filler – 0.5
pounds of Pentolite, steel cone of 78.7 grams weight, 48 mm diameter at open end, 68
mm in length and a 2.5 mm wall thickness. The nose cone standoff distance to the shape
charge is approximately 4 inches. Expected penetration of the shape charge is
approximately 3.5 to 4 inches of hardened armor plate.

3. Approximately 95% to 97% of the ordnance used at this site was training rounds (M7
A2/A3). However, the potential detonation of a HEAT round during mechanical
excavation and power screen processing poses a problem for protecting the equipment
operators. No test data was found which could substantiate the effective distance of the
“jet/slug” from the HEAT warhead with respect to detonation in a manner different from
intended use. That is, if the round detonated in free space and not at its optimum stand-
off distance for maximum armor penetration, at what distance could it penetrate the 9/16-
inch T 1 armor proposed to be used on the equipment?

4. Jet Research Center, a division of Halliburton, Inc., specializes in developing and
testing jet penetrators (shape charges) for use in oil well development and demolition
munitions. Dr, David Lydell is a specialist in shape charge design, having worked for the
U. S. Government in warhead development and design. Given the particular
characteristics of the 2.36-inch HEAT round he was able to model the effective standoff
distance for the proposed T 1 Armor. The modeling indicates that the jet/slug will not
penetrate the T 1 (9/16-inch) at a distance of about 13 feet. That is, the jet/slug is a
ballistic fragment without the capability to burn through the armor.

5. Historical records indicate that improvements in shape charge warhead design for the
2.36-inch HEAT round were conducted from 1946 through 1953. An improved round
(M6A5) was tested in the 1952 –1953 timeframe. The shape charge was changed to
include 0.97 pounds of Composition B explosive as a replacement for the Pentolite. This
extended the length of the warhead to the rear to accommodate the added explosives. All
other characteristic components appear to have remained the same. Extensive design and
development was completed on the nose cone and the shape itself since the proper
functioning of these two components control the capability to develop optimum
penetration of the warhead. A second round of modeling by Dr. Lydell indicates that the
added explosive has little effect on the 13-foot standoff distance for the equipment armor.
Most of the added explosive force resulted in more fragmentation effects for the round.

6. A records search of the Ft. McClellan Archives Search Report was conducted to
determine when the 2.36-inch rocket range was used and abandoned. Based on those
records, the range was active during and shortly after World War II. In 1947, Ft.
McClellan was inactivated. Ft. McClellan was re-activated in the 1951-1952 timeframe.
Troop training in use of anti-armor ordnance was not part of the next few years’ activity.
The records indicate that the 2.36-inch range was probably closed in the early 1950’s.
Therefore, the most likely scenario for the 2.36-inch rocket range is that the M6A3 will
be HEAT round used at the site for 2.36-inch rocket training.

Porter Morgan
Technical Manager
OE Removal Projects
Fort McClellan, AL
CEHNC-ED-CS-G

---

You can see the document here (but you may have to use the 'quick view' as PDF download was not working for me):

http://www.google.com/search?q=Part05_A ... tartPage=1

or try this:

http://docs.google.com/viewer?a=v&q=cac ... mEFtkU0oKA


Saxon Cross

THIS document is really really interesting!!

Seems like this is the most detailled report yet on the M6A3 concerning penetration and they even list their sources as wartime and post war official US army documents. This is fantastic news.

Although they also have quite a big range of penetration power from 89,9mm to 101,6mm. But still it is improved over the M6A1,

Thanks a lot for the links! Btw I managed to download the pdf, if you want it I can mail it to you?

Btw the weapons expert I contacted listed a similar penetration for the M6A3 being 105mm @30deg. He claims his sources as official EOD disposal manuals.

Btw how long did it take you to find those documents? I spent weeks scanning the internet and they didn't show up for me.

[Saxon Cross]

Hi Chris,

I agree that the inclusion of copper is just a rumor. I believe nations like the US and UK were experimenting with copper and shaped charges during WW2, but there’s no evidence copper made it into the M6A3. The ‘solid sounding’ source about copper I thought I had, turned out to be a guy on Tanknet who sounded like he knew what he was talking about, and claimed to have documents; but on closer inspection he failed to produced any docs, and seemed to be driven by nationalism.

The M6A1 document says this:

c. Effect.- (1) The rocket will penetrate 3" of homogeneous-steel armor plate at all ranges and at angles of impact as low as 30°.

I interpret this to mean the M6A1 will penetrate 3 inch (76mm) plate even if the angle of attack is as high as 30deg, but won't penetrate 3in plate at greater than 30deg angles.

My understanding is that to penetrate 3in (76mm) at 30deg requires a penetration of 3.5in (88mm), (because the jet has further to go to get through the plate).

In other words the M6A1 would penetrate 3in (76mm) plate up to 30deg, or up to 3.5in (88mm) if the rocket hit at 0 deg or 90 deg (straight on).

The penetration range we’re given for the M6A3 is 3.5in (88mm) to 4in (102mm). This is interesting because 3.5in (88mm) at 30deg is 4 inches (102mm).

It could be that the penetration of the M6A3 is 3.5in (88mm) plate at 30deg, or up to 4 inches (102mm) at 0 deg (90 deg).

Therefore the M6A3 possibly has 0.5in better penetration than the M6A1.
This additional 1/2inch would be the result of the improved ogive, which lowered the detonation time and gave a better stand-off distance.

If you really want to nail this down, the M6A3 doc has two names that you could possibly contact for additional clarification.

---

I'm not sure how typical these figures would be, they may be averages, or best expected results, not sure. I have MoD docs about the PIAT bomb penetration, and they say the results would vary greatly.

---
If you would email me the PDF document I’d appreciate it. You have my email address. Thanks.

I don’t know how long the document took to find. Once the search got under my skin, I kept coming back to it when I thought of a new search idea. Most of the promising documents seemed to be PDF, so I started putting “filetype:PDF” in most of my searches.

regards,
Saxon Cross

[LWD]

... c. Effect.- (1) The rocket will penetrate 3" of homogeneous-steel armor plate at all ranges and at angles of impact as low as 30°.

I interpret this to mean the M6A1 will penetrate 3 inch (76mm) plate even if the angle of attack is as high as 30deg, but won't penetrate 3in plate at greater than 30deg angles.
...

As written I would think the angle they are talking about would be the angle between the surface and the impact and not off normal. Your interpretation seems more reasonable though (i.e. 30 from normal rather than 60 from normal).

[Saxon Cross]

... c. Effect.- (1) The rocket will penetrate 3" of homogeneous-steel armor plate at all ranges and at angles of impact as low as 30°.

I interpret this to mean the M6A1 will penetrate 3 inch (76mm) plate even if the angle of attack is as high as 30deg, but won't penetrate 3in plate at greater than 30deg angles.
...

As written I would think the angle they are talking about would be the angle between the surface and the impact and not off normal. Your interpretation seems more reasonable though (i.e. 30 from normal rather than 60 from normal).

Hi LWD,

I agree. The only sensible interpretation is 30 deg from normal.

Three reasons:

1. 30 degrees (from normal) is often the standard used when citing armor penetration.

2. I don't think the M6A1 rocket would detonate if it hit at such a sharp angle. Which is why they had to change the shape of the ogive to a hemisphere for the M6A3.

3. A 3 inch (76mm) plate is 6 inches (152mm) of armor at 60deg (from normal). There's no way the M6A1 or M6A3 could penetrate 152mm of armor.




Saxon Cross

[Saxon Cross]

It turns out that I had an official unclassified US War Dept primary document on my PC this whole time with the penetration data for the Bazooka M6A3 rocket.

It confirms the official secondary document from earlier on this thread.
Penetration was 4 inches.






I didn't think that Field Artillery would include data on the Bazooka, so I didn't search the document.


cheers,
Saxon