Reversing bullets to increase penetration on Tanks

[Gateway Kid SASS# 70038 Life]

Some time back someone posted a link to an article on WWI soldiers pulling their bullets and reinserting them so the flat base was forward in order to increase the penetrating ability against tank armor. Am I misremembering which forum I saw that on or am I looking for a wives tale.

I will be using my admittedly weak google fu and try to look it up myself but any help would be appreciated.

Regards

   

Gateway Kid

[Pat Riot]

That makes no sense to me. 

[Abilene Slim SASS 81783]

Kid, this popped up when I pasted your thread title into Google. Scroll to “history” for the story. Interesting. 
 

https://en.m.wikipedia.org/wiki/Reversed_bullet

[Big Gus, SASS# 66666]

I was for many years a scientific and technical intelligence analyst for the US Army, I specialized in foreign armors. Here is my two cents.
During the First World War armor on tanks was very thin compared to later tanks 6 to 12 mm. (1/4 to 1/2 inch). 
The bullets fired by standard infantry rifle had a difficult time penetrating. How ever there is more than one way to cook a goose. One way to do this is to produce spall on the back face of the armor. Spall is when armor material flakes off the back side of the armor and flies about the inside of the vehicle. While in the case of WW1 tanks spall produced by a rifle bullet would not likely kill the tank it might injure or perhaps even kill the crew members. So how does reversing a bullet increase spalling. The reversed bullet would not penetrate the steel at all but it would transfer a lot of KE energy from the bullet to the armor plate when it hits. The ke energy is transferred into a shock wave propagating through the armor. When the wave hits the back wall of the armor it is reflected going back towards the front face but some of energy is going to cause the back face of the armor to bulge. The reflected wave going one way and the rear face bulging the other wave may cause a force inside the steel that exceeds its tensile strength resulting in the rear face of the armor flaking off producing spall fragments. Later on High explosive squash head (HESH) rounds were used to defeat tanks that could not otherwise be penetrated. HESH rounds used both KE energy and CE energy from the explosion to produce massive spall. The use of spaced armor or laminated armor can defeat spalling. 
So perhaps what our WW1 soldiers were trying to produce spall not actually penetrate the armor. 

[Gateway Kid SASS# 70038 Life]

25 minutes ago, Big Gus, SASS# 66666 said:

I was for many years a scientific and technical intelligence analyst for the US Army, I specialized in foreign armors. Here is my two cents.
During the First World War armor on tanks was very thin compared to later tanks 6 to 12 mm. (1/4 to 1/2 inch). 
The bullets fired by standard infantry rifle had a difficult time penetrating. How ever there is more than one way to cook a goose. One way to do this is to produce spall on the back face of the armor. Spall is when armor material flakes off the back side of the armor and flies about the inside of the vehicle. While in the case of WW1 tanks spall produced by a rifle bullet would not likely kill the tank it might injure or perhaps even kill the crew members. So how does reversing a bullet increase spalling. The reversed bullet would not penetrate the steel at all but it would transfer a lot of KE energy from the bullet to the armor plate when it hits. The ke energy is transferred into a shock wave propagating through the armor. When the wave hits the back wall of the armor it is reflected going back towards the front face but some of energy is going to cause the back face of the armor to bulge. The reflected wave going one way and the rear face bulging the other wave may cause a force inside the steel that exceeds its tensile strength resulting in the rear face of the armor flaking off producing spall fragments. Later on High explosive squash head (HESH) rounds were used to defeat tanks that could not otherwise be penetrated. HESH rounds used both KE energy and CE energy from the explosion to produce massive spall. The use of spaced armor or laminated armor can defeat spalling. 
So perhaps what our WW1 soldiers were trying to produce spall not actually penetrate the armor. 

Thanks so much Abilene Slim and Big Gus

Exactly what I needed.

I was thinking that was essentially what I remembered but getting a bit older fuzzes details a bit.

Regards

   

Gateway Kid

[Pat Riot]

1 hour ago, Big Gus, SASS# 66666 said:

I was for many years a scientific and technical intelligence analyst for the US Army, I specialized in foreign armors. Here is my two cents.
During the First World War armor on tanks was very thin compared to later tanks 6 to 12 mm. (1/4 to 1/2 inch). 
The bullets fired by standard infantry rifle had a difficult time penetrating. How ever there is more than one way to cook a goose. One way to do this is to produce spall on the back face of the armor. Spall is when armor material flakes off the back side of the armor and flies about the inside of the vehicle. While in the case of WW1 tanks spall produced by a rifle bullet would not likely kill the tank it might injure or perhaps even kill the crew members. So how does reversing a bullet increase spalling. The reversed bullet would not penetrate the steel at all but it would transfer a lot of KE energy from the bullet to the armor plate when it hits. The ke energy is transferred into a shock wave propagating through the armor. When the wave hits the back wall of the armor it is reflected going back towards the front face but some of energy is going to cause the back face of the armor to bulge. The reflected wave going one way and the rear face bulging the other wave may cause a force inside the steel that exceeds its tensile strength resulting in the rear face of the armor flaking off producing spall fragments. Later on High explosive squash head (HESH) rounds were used to defeat tanks that could not otherwise be penetrated. HESH rounds used both KE energy and CE energy from the explosion to produce massive spall. The use of spaced armor or laminated armor can defeat spalling. 
So perhaps what our WW1 soldiers were trying to produce spall not actually penetrate the armor. 

Okay, now this makes sense. 

 

Thanks Big Gus. 

[Lawdog Dago Dom]