armor vs ammo - known facts

[Marine Cpl]

OK lets take a 55gr and 62gr TSX ...

The 62gr wins because it is not just the speed that is more than enough but the extra momentum. In terms of punching through and killing
potential there might be a very small difference but the 62gr always wins.


Ballistics Results - 55gr tsx
Range (yards) Velocity (fps) Energy (ft.-lb.) Trajectory (in) Come UP in MOA Come UP in Mils Wind Drift (in) Wind Drift in MOA Wind Drift in Mils
Muzzle 3200 1250 -1.5 0 0 0 0 0
100 2739 916 0 0 0 0 0 0
200 2322 658 -3.2 1.5 0.4 0 0 0
300 1943 461 -12.9 4.1 1.2 0 0 0
400 1607 315 -31.9 7.6 2.2 0 0 0
500 1325 214 -64.6 12.3 3.6 0 0 0

Ballistics Results - 62gr tsx
Range (yards) Velocity (fps) Energy (ft.-lb.) Trajectory (in) Come UP in MOA Come UP in Mils Wind Drift (in) Wind Drift in MOA Wind Drift in Mils
Muzzle 3000 1239 -1.5 0 0 0 0 0
100 2674 984 0 0 0 0 0 0
200 2371 774 -3.4 1.6 0.5 0 0 0
300 2088 600 -13 4.1 1.2 0 0 0
400 1826 459 -30.6 7.3 2.1 0 0 0
500 1588 347 -58.8 11.2 3.3 0 0 0

What are you showing me there? What does that have to do with what I'm saying in regards to penetrating steel. The 62 gr will probably penetrate a medium barrier like wood more due to the weight but not steel. My arguments are only in regards to hard objects like steel. Soft objects and medium objects rely on grain. (Momentum) Hard objects rely on speed.

62 gr is a compromise. 77 gr is good for animals that require penetration in soft tissue. 55 gr is good for steel.

The same goes for 9mm with light, medium, and heavy grains.

 

[Podmonkey]

So what's the curve here? Is there a point where projectile mass becomes the determining factor of AP, despite lower velocites. Or is it a case of requiring disproportionate velocity increases as projectile weight goes up?

 

[Podmonkey]

Where does frontal area and sectional density come in vs velcocity and mass?

 

[Marine Cpl]

Where does frontal area and sectional density come in vs velcocity and mass?

It plays a factor. Those pointed 9mm rounds penetrated armor. But even those will fail if velocity is not up.

 

[Podmonkey]

It plays a factor. Those pointed 9mm rounds penetrated armor.

But whats the precise relationship? Thats what I'd like to test for.
In 30-06 isn't the M2 AP heavier and slower than the M1 ball? That would indicate a non linear curve here.

 

[meketrefe]

What are you showing me there? What does that have to do with what I'm saying in regards to penetrating steel. The 62 gr will probably penetrate wood more due to the weight but not steel. My arguments are only in regards to hard objects like steel. Soft objects and medium objects rely on grain. (Momentum) Hard objects rely on speed.

62 gr is a compromise. 77 gr is good for animals that require penetration in soft tissue. 55 gr is good for steel.

Not just other media. The 62gr will punch through steel better than the 55gr. At 100 yards it is caught up with the 55gr in terms of speed
and then you have the same construction yet the additional sectional density and momentum of the 62gr.
At short ranges there is not enough difference in speed to compensate for all other attributes.
That is why the 55gr bullets didn't advance and the 62gr did. It is a matter of trade-offs always.

 

[Marine Cpl]

Not just other media. The 62gr will punch through steel better than the 55gr. At 100 yards it is caught up with the 55gr in terms of speed
and then you have the same construction yet the additional sectional density and momentum of the 62gr.
At short ranges there is not enough difference in speed to compensate for all other attributes.
That is why the 55gr bullets didn't advance and the 62gr did. It is a matter of trade-offs always.

Did you see that video where regular 55 gr punched through plate where 62 gr penetrator failed?

What you are saying is correct. At a distance for example 300 yards, the 62 gr will retain more speed but at that point it has slowed down enough that neither the 55 gr nor the 62 gr will potentate that armor due to both being under the required velocity to do so.

 

[Marine Cpl]

But whats the precise relationship? Thats what I'd like to test for.
In 30-06 isn't the M2 AP heavier and slower than the M1 ball? That would indicate a non linear curve here.

I think the bullet construction plays a factor in that case. The FMJ at a slightly higher velocity may break up. The AP doesn't break up insuring penetration.

For example. Lets say it requires 3000 fps to penetrate steel x. A FMJ going at 3300 should do it but it doesn't because the jacket and lead flattens itself out upon impact but the slightly slower AP going at exactly 3000 fps goes through because it stays together.

 

[meketrefe]

Did you see that video where regular 55 gr punched through plate where 62 gr penetrator failed?

What you are saying is correct. At a distance the 62 gr will retain more speed but at that point it has slowed down enough that neither the 55 gr or the 62 gr will potentate that armor.

Look at the trajectory, why something at virtually the same speed and more grain and extra SD will not work better? Physics do not lie.

I didn't see any videos but from experience I can tell you almost any FMJ will stop in hard steel like a plate of hot rolled steel whereas the modern
ammo in 62gr will punch through. Even in milder steel we have those 3/4 plates at the range where some idiots hit the top with fmj rounds including
bi-metal ak rounds, blackout, 55gr fmjs... you name it and all they do is a mushroom yet the 62gr service ammo will punch clean.
When it comes to those speeds marginal gains even in one case demonstrated effect might not be taken as the demonstration that dictates the rule.
Who knows maybe there is a type of material or construction where that might make a difference at short-range with a hyper velocity but for
most of hard barriers, materials and armor the 62gr is on top even the now retired M855 and w/o getting into more advanced rounds.
We could exchange opinions all day but this technology has been researched and tested over the years by scientist and fired millions of rounds
to decide that was the best they could do at the time. Nothing a single youtuber can ever do and demonstrate in arbitrary set of circumstances.
I am not saying one person with a nice rifle and nice camera cannot demonstrate something. In fact a few you tubers do a good job at being
objective and pragmatic and provide certain value aside from all the other commercial garbage but I am also saying lets consider the science
of terminal ballistics and all the facts and documentation scientists and official organisms have published through the years.

 

[Marine Cpl]

Look at the trajectory, why something at virtually the same speed and more grain and extra SD will not work better? Physics do not lie.

I didn't see any videos but from experience I can tell you almost any FMJ will stop in hard steel like a plate of hot rolled steel whereas the modern
ammo in 62gr will punch through. Even in milder steel we have those 3/4 plates at the range where some idiots hit the top with fmj rounds including
bi-metal ak rounds, blackout, 55gr fmjs... you name it and all they do is a mushroom yet the 62gr service ammo will punch clean.
When it comes to those speeds marginal gains even in one case demonstrated effect might not be taken as the demonstration that dictates the rule.
Who knows maybe there is a type of material or construction where that might make a difference at short-range with a hyper velocity but for
most of hard barriers, materials and armor the 62gr is on top even the now retired M855 and w/o getting into more advanced rounds.
We could exchange opinions all day but this technology has been researched and tested over the years by scientist and fired millions of rounds
to decide that was the best they could do at the time. Nothing a single youtuber can ever do and demonstrate in arbitrary set of circumstances.
I am not saying one person with a nice rifle and nice camera cannot demonstrate something. In fact a few you tubers do a good job at being
objective and pragmatic and provide certain value aside from all the other commercial garbage but I am also saying lets consider the science
of terminal ballistics and all the facts and documentation scientists and official organisms have published through the years.

That's what I said in a previous post. Bullet construction plays a factor too. That is why I'm a fan of solid copper. While not as hard as an AP, it is better than lead with a jacket that'll flatten if the barrier is hard enough.

 

[meketrefe]

I think the bullet construction plays a factor in that case. The FMJ at a slightly higher velocity may break up. The AP doesn't break up insuring penetration.

For example. Lets say it requires 3000 fps to penetrate steel x. A FMJ going at 3300 should do it but it doesn't because the jacket and lead flattens itself out upon impact but the slightly slower AP going at exactly 3000 fps goes through because it stays together.

But even if it is not an AP round that is another whole ball game all together. when we introduce some extra steel and also some additional lead grain
we increase the potential of that round by increasing the sectional density and the stoutness of the round and w/o getting into AP designs.
That was the whole idea of the ARMY going form the Vietnam Era 55gr to 62gr in order to increase letality and also provide a relatively superior
effectiveness in soothing at vehicles through glass and doors, etc... That is, even with all the shortcomings of the light 22 caliber it became a
superior round to the AK round or any of the other alternatives like the 5.45.
Even all other things being equal a 62gr FMJ is a better round than the 55gr just because of the weight retention, speed retention and additional
SD. The only problem is not massively adopted from previous Mil spec design so it is not as plentiful and/or economic but in some cases is the
same price and a better round. Like I said there is not enough difference in short range speed to prove the 55gr is better and as we get to
100 yards the speeds are the same and the 62gr wins in every department.

 

[meketrefe]

That's what I said in a previous post. Bullet construction plays a factor too. That is why I'm a fan of solid copper. While not as hard as an AP, it is better than lead with a jacket that'll flatten if the barrier is hard enough.

It depends on the jacket. Some russian fmjs are so hard that they behave like solids when punching and then they break apart but then
they are not that consistent (accuracy) and they are hard on the rifling and barrel.
Like always there is a tradeoff somewhere.

 

[Marine Cpl]

But even if it is not an AP round that is another whole ball game all together. when we introduce some extra steel and also some additional lead grain
we increase the potential of that round by increasing the sectional density and the stoutness of the round and w/o getting into AP designs.
That was the whole idea of the ARMY going form the Vietnam Era 55gr to 62gr in order to increase letality and also provide a relatively superior
effectiveness in soothing at vehicles through glass and doors, etc... That is, even with all the shortcomings of the light 22 caliber it became a
superior round to the AK round or any of the other alternatives like the 5.45.
Even all other things being equal a 62gr FMJ is a better round than the 55gr just because of the weight retention, speed retention and additional
SD. The only problem is not massively adopted from previous Mil spec design so it is not as plentiful and/or economic but in some cases is the
same price and a better round. Like I said there is not enough difference in short range speed to prove the 55gr is better and as we get to
100 yards the speeds are the same and the 62gr wins in every department.

Again. Bullet construction. All things being equal, a 55 gr penetrator round will penetrate steel better due to velocity than the 62 gr penetrator round yet the 62 gr will penetrate wood better than the 55 gr penetrator. It depends on the barrier. If it's steel, the faster and lower grain wins. If it's brick, wood, or mud hut, the 62 gr penetrator wins.

It's all compromise based on the type of barrier presented. The military went 62 gr penetrator for uniformity because their M249 SAW required it for certain barriers at a cost of fragmentation at close distance in a body with the 55 gr.

Compromise.

 

[meketrefe]

Here some guys shooting all sort of steel...
When you get to the 3/8 hot rolled one can see the importance of mass and momentum with the 308 fmj
vs the faster 55gr fmj.
When the jacket has enough mass that can push through it leaves a nice flared entry and exit.
I am not sure why they keep saying AP round for the SS109 when it is not an AP round. youtubers I guess!
I wish the had tested a 90gr 6.8 spc to show how effective that is too vs. the AK, blackout and others
that will fail to punch through the metal.
Also add auto glass that is one of the hardest things to overcome.

 

[meketrefe]

Here some guys shooting all sort of steel...
When you get to the 3/8 hot rolled one can see the importance of mass and momentum with the 308 fmj
vs the faster 55gr fmj.
When the jacket has enough mass that can push through it leaves a nice flared entry and exit.
I am not sure why they keep saying AP round for the SS109 when it is not an AP round. youtubers I guess!
I wish the had tested a 90gr 6.8 spc to show how effective that is too vs. the AK, blackout and others
that will fail to punch through the metal.
Also add auto glass that is one of the hardest things to overcome.

 

[Marine Cpl]

There is still a threshold were a certain amount of mass is required for that one barrier. I'm not saying that a 10 gr bullet going at 5000 fps will go through.

That particular steel barrier may need x amount of mass and y amount of speed. You still need both.

 

[meketrefe]

There is still a threshold were a certain amount of mass is required for that one barrier. I'm not saying that a 10 gr bullet going at 5000 fps will go through.

That particular steel barrier may need x amount of mass and y amount of speed. You still need both.

correct.
So the speed gain of the 55gr over a 62gr becomes irrelevant because the 62gr with the better ballistics coefficient
catches up quickly with the higher 55gr speed at the muzzle and it only gets better after 100 yards, 200yards, and so on.
So at the average range at the comparable striking speeds the additional momentum and SD of the 62gr wins.
You see, the 12% difference in weight only sends the bullet 3% faster and even if it did even faster, the better ballistics
will catch up pretty quickly. That is what the two TSX in 55gr and 62gr trajectories say above.
If we get a M855 I don't know what to compare it to steel tip wise since I never got to find XM777 surplus ammo but I do have
the speeds of a huge number of 5.56 rounds both civilian and surplus tested by my from 16", 18" and 20" ARs as
well as some bolt action too.
What would be the comparison to with what ammo and what is the speed if we stay with the precise same construction?
I bet it doesn't make a difference in speed.

...
I bet even if we took SS190 projectiles and put them in the 223 would not see a practical advantage over the classic M885.

 

[Marine Cpl]

correct.
So the speed gain of the 55gr over a 62gr becomes irrelevant because the 62gr with the better ballistics coefficient
catches up quickly with the higher 55gr speed at the muzzle and it only gets better after 100 yards, 200yards, and so on.
So at the average range at the comparable striking speeds the additional momentum and SD of the 62gr wins.
You see, the 12% difference in weight only sends the bullet 3% faster and even if it did even faster, the better ballistics
will catch up pretty quickly. That is what the two TSX in 55gr and 62gr trajectories say above.
If we get a M855 I don't know what to compare it to steel tip wise since I never got to find XM777 surplus ammo but I do have
the speeds of a huge number of 5.56 rounds both civilian and surplus tested by my from 16", 18" and 20" ARs as
well as some bolt action too.
What would be the comparison to with what ammo and what is the speed if we stay with the precise same construction?
I bet it doesn't make a difference in speed.

...
I bet even if we took SS190 projectiles and put them in the 223 would not see a practical advantage over the classic M885.

What you say is correct for soft to medium barriers at distance. Grain wins in that case at distance. Not so at short range for steel barriers if it doesn't reach the required velocity. At long range the velocity has dropped where neither will penetrate the same steel barrier so in that case the 62 gr wins for other softer barriers.

This thread is about steel armor at close range right? No one is going to try to penetrate armor at 200 yards. It would need the high muzzle velocity at that range. Both grains would drop below the threshold at that point.

 

[meketrefe]

What you say is correct for soft to medium barriers at distance. Grain wins in that case at distance. Not so at short range for steel barriers as if it doesn't teach the required velocity. At long range the velocity has dropped where neither will penetrate the same steel barrier so in that case the 62 gr wins for other softer barriers.

This thread is about steel armor at close range right? No one is going to try to penetrate armor at 200 yards. It would need the high muzzle velocity at that range.

At close range there is plenty of velocity with both and enough velocity with the 62gr to perform as prescribed.
At 100 yards the velocity is virtually the same but the 62gr has more momentum and SD.
At 200-300 and even 500 yards there still a need to penetrate when we shoot vehicles through doors and glass.
That is another reason yet into the next step of the evolution and why it was found Liberty's arrowhead designed not
only met all requirements but exceeded all expectations. This even after all the major redesign from tungsten to
hardened steel due to the contamination concerns. And also the law suit the Army lost after Liberty sued them
from steeling their design. What do they care right?.. the taxpayers pay for the fiasco.

Anyway, there are real tactical needs and after a lot of time and money on the research and millions of
rounds fired the bullet is 62grains and not 55gr or lighter. The 62gr comes out a 16" carbine at 3,000 fps avg and
because of the arrowhead it beats any other preexisting FMJ or steel tipped including the 308 winchester fmj at a distance
in terms of hard barrier penetration. We could say one could not do better with either a lither or a heavier round
based on design and materials.

Data Dump: Army 'Black Tip' Ammo - Kit Up!

That is why the decision to apply the same directives to the 308 for military use.
The thing is, this is harder to justify because the 308 fmj does so well and it is cost effective
and in most targets just the mass and momentum alone are enough to make it a more
effective option when distances increase and also to tackle larger and harder targets.

 

[Marine Cpl]

At close range there is plenty of velocity with both and enough velocity with the 62gr to perform as prescribed.
At 100 yards the velocity is virtually the same but the 62gr has more momentum and SD.
At 200-300 and even 500 yards there still a need to penetrate when we shoot vehicles through doors and glass.
That is another reason yet into the next step of the evolution and why it was found Liberty's arrowhead designed not
only met all requirements but exceeded all expectations. This even after all the major redesign from tungsten to
hardened steel due to the contamination concerns. And also the law suit the Army lost after Liberty sued them
from steeling their design. What do they care right?.. the taxpayers pay for the fiasco.

Anyway, there are real tactical needs and after a lot of time and money on the research and millions of
rounds fired the bullet is 62grains and not 55gr or lighter. The 62gr comes out a 16" carbine at 3,000 fps avg and
because of the arrowhead it beats any other preexisting FMJ or steel tipped including the 308 winchester fmj at a distance
in terms of hard barrier penetration. We could say one could not do better with either a lither or a heavier round
based on design and materials.

Data Dump: Army 'Black Tip' Ammo - Kit Up!

That is why the decision to apply the same directives to the 308 for military use.
The thing is, this is harder to justify because the 308 fmj does so well and it is cost effective.

You are not getting it. Again what you say is correct for soft and medium barriers like people, animals, wood, mud bricks, ect.

It is not the case for penetrating steel at close range. Grain at slower speeds loses for that.

Look at the video below. The 55 gr goes right through. The 62 gr fails. Now if you move that plate to 200 yards, they will both fail. How will grain win at 200 yards if it couldn't do it at 10 yards for steel?


Now if a car door at 200 yards requires X amount of speed and grain to penetrate, the 62 may have both while the 55 may have the grain required but no longer the speed required due to losing it at that distance faster than the 62 gr did.

 

[meketrefe]

You are not getting it. Again what you say is correct for soft and medium barriers like people, animals, wood, mud bricks, ect.

It is not the case for penetrating steel at close range. Grain at slower speeds loses for that.

Look at the video below. The 55 gr goes right through. The 62 gr fails. Now if you move that plate to 200 yards, they will both fail. How will grain win at 200 yards if it couldn't do it at 10 yards for steel?


Now if a car door at 200 yards requires X amount of speed and grain to penetrate, the 62 may have both while the 55 may have the grain required but no longer the speed required due to losing it at that distance faster than the 62 gr did.

What a useless test.
The M193 from lake city is one of the fastest rounds one can buy and from a bolt action
even faster at that ridiculous range of 7ft.
With the 62gr why he didn't measure the speed first like he did with the 55gr? ...
But most important why is he not using a 62gr FMJ of the same construction loaded at the same pressure?

I don't even know who makes that body armor but this is what I learn from this:

A) I see some pretty shitty body armor if that is supposed to be AR500 / type III type of deal.
B) The 62gr ammo is probably a pretty shitty whatever he is using.
C) Nobody should be doing tests shooting hardened steel at 7 yards. It is foolish and plain dangerous.

Even with 55gr ammo there is a huge difference of up to 300 fps between one brand and another.
Same thing happens with 62gr ammo. The ideal would be to test a high pressure
62gr fmj round vs the 55gr fmj round at a more typical distance like 25 to 50 yards.

In a previous video we posted the 3/8 hot rolled steel stops the 55gr fmj while the SS109 punches through.
One needs to be careful with youtube. These youtubers show effects in a set of situations but they say
nothing about the overall effectiveness of 55gr vs 62gr 223 type rounds. Mixing peaches and oranges
type of deal.

 

[Marine Cpl]

What a useless test.
The M193 from lake city is one of the fastest rounds one can buy and from a bolt action
even faster at that ridiculous range of 7ft.
With the 62gr why he didn't measure the speed first like he did with the 55gr? ...
But most important why is he not using a 62gr FMJ of the same construction loaded at the same pressure?

I don't even know who makes that body armor but this is what I learn from this:

A) I see some pretty shitty body armor if that is supposed to be AR500 / type III type of deal.
B) The 62gr ammo is probably a pretty shitty whatever he is using.
C) Nobody should be doing tests shooting hardened steel at 7 yards. It is foolish and plain dangerous.

Even with 55gr ammo there is a huge difference of up to 300 fps between one brand and another.
Same thing happens with 62gr ammo. The ideal would be to test a high pressure
62gr fmj round vs the 55gr fmj round at a more typical distance like 25 to 50 yards.

In a previous video we posted the 3/8 hot rolled steel stops the 55gr fmj while the SS109 punches through.
One needs to be careful with youtube. These youtubers show effects in a set of situations but they say
nothing about the overall effectiveness of 55gr vs 62gr 223 type rounds. Mixing peaches and oranges
type of deal.

I guess you don't like the results so now you come up with excuses. I thought you were above that unlike others on this forum.

One, He used the same barrel for both. So that was equal.

Two, It's obvious that the 55 gr was faster then the 62 gr. It doesn't matter if the 62 gr was a penetrator or not. It didn't make it due to being slower. Both were Xm Lake City rejects that you can buy.

Three. The range he shot it at for safety's sake makes no difference. That's the range that will be used when your door is kicked in. At 100 or 200, neither would have penetrated due to both rounds slowing down.

 

[Podmonkey]

I declare we three take a vacation and do AP testing!

 

[Marine Cpl]

I declare we three take a vacation and do AP testing!

And when we do speed at steel will win and you guys will pay for the drinks.

It's the same concept for pistol rated vests. (Not Level 3). A 9mm will NOT make it through but a 9mm on steroids of the same grain (.357 Magnum or SIG of the 125 gr variety) will. Velocity rather then grain will win.

A 147 gr will not make it through but a 90 gr +P+ will. There are numerous tests that show this.

 

[Podmonkey]

And when we do speed at steel will win and you guys will pay for the drinks.

It's the same concept for pistol rated vests. (Not Level 3). A 9mm will NOT make it through but a 9mm on steroids of the same grain (.357 Magnum or SIG of the 125 gr variety) will. Velocity rather then grain will win.

A 147 gr will not make it through but a 90 gr +P+ will. There are numerous tests that show this.

You can piddle about with handguns if you want, I'm doing 5.56 AR and 30-06 Garand testing baby!

 

[Marine Cpl]

You can piddle about with handguns if you want, I'm doing 5.56 AR and 30-06 Garand testing baby!

Okay. Let me know what happens. Physics is the same in regards to pistols and rifles.

 

[Podmonkey]

Okay. Let me know what happens. Physics is the same in regards to pistols and rifles.

Chillax brah! Testing is just farting around with guns and having fun! I have heavy deffensive/practical prerequisites for my "serious" guns but being fun is still number 1 priority!

 

[Marine Cpl]

Chillax brah! Testing is just farting around with guns and having fun! I have heavy deffensive/practical prerequisites for my "serious" guns but being fun is still number 1 priority!

Why do you think I'm not chilled? I always am.

 

[Podmonkey]

Why do you think I'm not chilled? I always am.

You don't sound chilled. You sound vexxed. Come to PA. We will shoot naughty stuff. Or maybr we shoukd go to @Bullet Guy's and shoot really naughty stuff!

 

[meketrefe]

Will,
It is not about liking or not liking the results but about following some
method or something, it doesn't have to be too scientific but something that makes sense.
What is the point of a 55gr lake city shot from a 22 bolt action at 7 yards and
punching through some questionable type III body armor? It proves that speeds matters
like we already know but with the typical firearm and typical range it doesn't make a darn
difference.
The M193 nor the M855 where designed with that scenario in mind.
Let me give you an example on how ammo brand and batch make a big difference:
A 55gr FMJ from PMC is advertised at 3100fps from a 16" AR yet it comes out at 2800fps
measured with two of my cronos.
Same things happen with countless other ammo with the Lake City plant 55gr being the fastest
shooter from 20" AR and up. It also runs hotter than the average round.
So not all "green tips" brands have the same speed nor they should be tested for that purpose
as there are other rounds better suited for that purpose.
When you get to 16" AR the modern M885A1 closes the gap faster since it was optimized
for shorter barrels.
That is why I suggest to take a 55gr FMJ and comparing with a 62gr FMJ loaded at the
same pressure (oranges to oranges). The speeds are very similar and at only 75 yards
the 62gr comes on top in any test including armor or any other barrier. This w/o getting
into more sophisticated or complex tests.
Shooting M193 with a long bolt action at 7 yards is simply useless info.