Portable twelve pounders as a bodyguard?

KNick wrote:
A standard 30-06 round will punch cleanly through 2 separate 1" cold-rolled steel plates 8 feet apart, show deformation on the third and still be intact enough to ricochet off of the 4th (angled) plate.

Not fired from a pistol-length barrel it wont.


And more importantly:
"A standard 30-06 round will punch cleanly through 2 separate 1" cold-rolled steel plates 8 feet apart"

No, it wont, that´s a complete rubbish claim.

This is what happens against a SINGLE 1 inch steelplate:
https://www.youtube.com/watch?v=BsksLpDo_4o
https://www.youtube.com/watch?v=3KgRPpUx4_g

Not quite *splat*, but zero penetration

At 8:30 here:
https://www.youtube.com/watch?v=hzYH8ap1TDo
you see 30-06 armourpiercing ammo being stopped by 1.5" SOFT steel.
And HALF an inch of steel armour.

And breastplates have more in common with the armour than with the soft steel plates.

While breastplates are relatively thin, meaning that projectile overmatch has to be accounted for as well, they do not count as soft steel.


I expect you or whoever gave you that faerytale have mistaken 1" with 1/4".

=2014/06/18=
Hi Guys

?? What does MOA mean ??

R
.

kbus888 wrote:=2014/06/18=
Hi Guys

?? What does MOA mean ??

R
.

Mentioned on the first page, "Minute of Angle".

n7axw wrote:
You are referring to the demonsration that Merlin gave to Protector Stohnar and Cayleb in LAMA. IIRC those pistols did have the capability of using the rifle round but had shorter barrels. That would mean that they were pistols, not rifles, with lower muzzle velocity and shorter range. Do I have that right?

Don

Yes, the round's velocity when it was shot from a pistol would not be as high as it would be through a full length rifle (6 or 8 inches versus 24+ inches). With black powder, the time needed to get a complete burn of the powder charge is much longer. If you want maximum velocity, you need a long barrel to get a more complete burn of the powder while the bullet is still in the barrel. The velocity of the rifle round being fired from a pistol would be significantly less than if the same round was fired from the rifle. How significant, I can't really say. call it a 40-60% reduction. How much of a loss would depend not only on the actual barrel length but on the cylinder gap as well.

But.

Bullet weight and composition- not just sheer velocity- has a great deal to do with penetration. The heavier rifle bullet would retain more momentum than the lighter pistol bullet. The harder alloy (lead with a higher percentage of tin and 'false silver' or antimony) would not deform as quickly upon hitting a hard surface like the armor.

I've seen this happen in real life during my years of competing in Cowboy Action Shooting.

I've witnessed 250gr cast lead bullets using a hard alloy .45 Colt bullets loaded to 900-1000fps from a handgun go through a 1/4" to 3/8" steel plate like a hole puncher through a sheet of paper at a distance of 30-45 feet.

Take the same bullet mold and use pure lead or a soft alloy like wheel weights when casting the bullets and it will mushroom on contact and leave a little disc of lead laying on the ground at the base of the target. A soft alloy or pure lead bullet will immediately expand upon hitting a steel plate and leaves no damage to the plate other than a smear of lead that marks the point of impact.

The breast plates aren't going to be that thick. They would be too heavy to wear. The rifle round has a heavier bullet and, while attaining 1000fps with it from Merlin's pistols may be a stretch, that weight would help counteract the loss of velocity and aid in penetration. There's already documentation in the books that the rounds are not only made of a hard alloy but also gaschecked so they can attain as close to the maximum velocity available for lead bullets.

jtg452 wrote:The breast plates aren't going to be that thick. They would be too heavy to wear.

A replica breastplate made today would not no.

But historical breastplates were not made from plate of the same thickness all over.

While 1/4" might be a stretch in general, a decent breastplate will vary from 1 to 5mm.
But some of the heavier ones in history went above 1/4" in the most protected areas.
IIRC, the thickest historical breastplate i´ve read of had 9mm in the thickest area.

And again, DO remember that historically, breastplates were sold only AFTER being fired on at just a few meters distance, with the impact mark being used as a quality stamp.

Breastplates were made capable of the wearer not being wounded by a hit from a 0.68 musket up close. Those were not too heavy to wear.

And there was a criminal in Australia early 20th century who made himself an armour that covered him almost completely, and then "went to town", the police used up hordes of bullets before taking him down, by shooting at the soles of his feet as he walked. Those were the only places his armour couldn´t prevent the bullets from causing real harm.

While the total weight for that was pretty heavy, the guy still walked around in it, fought the police with it on, and their guns and rifles failed to penetrate to cause more than some inconsequential light injuries.

IIRC, it was something in the ~20kg range.

jtg452 wrote:Bullet weight and composition- not just sheer velocity- has a great deal to do with penetration. The heavier rifle bullet would retain more momentum than the lighter pistol bullet.
...
The rifle round has a heavier bullet and, while attaining 1000fps with it from Merlin's pistols may be a stretch, that weight would help counteract the loss of velocity and aid in penetration.

While you are not exactly incorrect, armour penetration favours high velocity rounds.

And generally, if you punch through more "by weight", the bullet will loose a LOT of its energy in the process.

Essentially, for a slower, heavier bullet to punch through the same armour, it will need more total energy than a smaller, higher velocity bullet.

Dependent on caliber and bullet types of course.

Tenshinai wrote:
A replica breastplate made today would not no.

But historical breastplates were not made from plate of the same thickness all over.

While 1/4" might be a stretch in general, a decent breastplate will vary from 1 to 5mm.
But some of the heavier ones in history went above 1/4" in the most protected areas.
IIRC, the thickest historical breastplate i´ve read of had 9mm in the thickest area.

And again, DO remember that historically, breastplates were sold only AFTER being fired on at just a few meters distance, with the impact mark being used as a quality stamp.

Breastplates were made capable of the wearer not being wounded by a hit from a 0.68 musket up close. Those were not too heavy to wear.

And there was a criminal in Australia early 20th century who made himself an armour that covered him almost completely, and then "went to town", the police used up hordes of bullets before taking him down, by shooting at the soles of his feet as he walked. Those were the only places his armour couldn´t prevent the bullets from causing real harm.

While the total weight for that was pretty heavy, the guy still walked around in it, fought the police with it on, and their guns and rifles failed to penetrate to cause more than some inconsequential light injuries.

IIRC, it was something in the ~20kg range.

Where the armor/steel thickness is concerned, we are talking past each other while saying basically the same things. Or at least close enough that it's not a real impact.

5mm is roughly 2/10th's of an inch (.20"- .196" to be precise) and 9mm equates to a little more than 1/3 an inch at .354". 1/4 of an inch is .25" and 3/8 is .375".

Close enough for our theoretical supposition work, AFAIC.

Tenshinai wrote:
While you are not exactly incorrect, armour penetration favours high velocity rounds.

And generally, if you punch through more "by weight", the bullet will loose a LOT of its energy in the process.

Essentially, for a slower, heavier bullet to punch through the same armour, it will need more total energy than a smaller, higher velocity bullet.

Dependent on caliber and bullet types of course.

Here's a link to the spoiler I pulled the numbers from

viewtopic.php?f=7&t=4850&p=117375#p117375

RFC's posting of the spoiler with the information is a little way down the page.

I ran the rifle round's numbers for ballistic coefficient and muzzle energy.

I used the BC computer at FederalPremium.com and the muzzle energy calculator at Ballistics101.com if you want to play with them a little on your own.

A 500gr spitzer has a BC of around 0.694. At 1600fps, the Muzzle Energy is 2842 foot pounds. At 1000fps, the ME is 1110 foot pounds.

The 250gr .45Colt round I mentioned above doing 1000fps that punched through the steel plates has a ME of 555, or half the energy just like you'd expect.

The .45Colt round was using a RNFP (round nose, flat point) cast lead bullet. While I don't know exactly which manufacturer's mold was used to make it, I can hazard a guess at the width of the contact surface at the point of the bullet and I figure it to be someplace in the neighborhood of .20". The flat point is designed so it is bigger in diameter than a large primer so it can be used in a horizontal or tubular magazine. With the wide nose of the bullet profile, to punch it through something is a brute force application. It would be like trying to drive a finishing nail into a piece of wood while head first instead of using the pointed end.

The M96 rifle round, on the other hand, uses a pointed bullet, so the contact surface is much smaller- how big it actually is I have no idea but I assume since it's designed for a vertical magazine rifle, it really comes to a point like modern rifle bullets designed for the same use.

Add to all of that the fact that the bullet in question is designed to be fired at a much higher velocity. The M96 round is designed to work at 1600+ fps. To push a lead bullet that fast, the lead alloy used to make the projectile must be harder and there is a mention in the text of them quenching the bullets to increase the hardness as well.

So we have a bullet that is as hard or (probably) harder than a modern round that has been seen by first hand witnesses performing, that weighs twice as much, going just as fast with a much smaller point of contact. I have no problem believing that it will perform just as advertised. The numbers are there.

Speaking of numbers, someone mentioned modern rifle rounds so I played a bit with the ME calculator while I had the Federal site up on another tab.

Federal's 150gr .308 round (the one on the top of the list- I was lazy and didn't look any further) has a listed velocity of 2820fps. That gives it a ME of 2596foot pounds (compared to the M96 500gr @ 1600fps ME of 2842). If you shoot the 150gr .308 from a pistol and end up with a 1400fps velocity (a plausible velocity from a barrel as short as 6 inches), it drops down to 653foot pounds. The pistol round that RFC developed is 350gr @1000fps and it has a ME of 777 foot pounds from a 6 inch barrel.

KNick wrote:

Tenshinai wrote:Still though, even a full out rifleround shouldn´t be knocking holes THAT easily in thick metal plates, plural, and then still have lots of energy left.

A standard 30-06 round will punch cleanly through 2 separate 1" cold-rolled steel plates 8 feet apart, show deformation on the third and still be intact enough to ricochet off of the 4th (angled) plate.

This is more likely what Merlin was shooting at 3 layer of modern mild steel. Weapons were a AR15 and 30-06 and they both pushed through the steel before going on through a post. Bullets were traveling at over 2600 ft/sec, probable bullet weigh 55gr for the AR15 150 gr for the 30-06. Newer AR15 bullets are 62gr copper steel penetrator. An 1 inch of tempered or harden steel should be poof against most hand held weapons without armor piercing ammo.

50lb is about the limit most people can carry for long distance 8-10hr day marches. Try it some times and see how wearing it is to carry a 40-50lb pack for any long distant. Then imaging carrying the armor and rest of the battlefield kit. Weapon, Water, Food, Blanket, Ammo, Spare clothes, Wet Weather Gear, Tent, Flint Steel and Tender, Mess Equipment, and anything else you will need to survive.

https://www.youtube.com/watch?v=OtP88D6r9bg

jtg452 wrote:I used the BC computer at FederalPremium.com and the muzzle energy calculator at Ballistics101.com if you want to play with them a little on your own.

Nah, i generally leave that to the severe gun-nuts.

I´m more interested in the results and WHY the results are as they are than the number crunching.

My focus is on history and how some technology affected events.

jtg452 wrote:The .45Colt round was using a RNFP (round nose, flat point) cast lead bullet. While I don't know exactly which manufacturer's mold was used to make it, I can hazard a guess at the width of the contact surface at the point of the bullet and I figure it to be someplace in the neighborhood of .20".

Fail. A cast lead bullet hitting steel will start to deform instantly on impact, as such the contact surface may effectively be that of the caliber of the bullet, or more, or less all depending on exact hardness of the metals involved and impact properties.

So, the impact area will be anything from your suggested .2" up to maybe .6".

In this there´s also the overmatch effect to consider, you WANT a wider impact area than the armour is thick as otherwise the effect will work against the penetration.

And with a slow and large bullet, that will equate to poor penetration because it will spend a LOT of energy going *splat* against the breastplates.

jtg452 wrote:With the wide nose of the bullet profile, to punch it through something is a brute force application.

Yes, and the softer the bullet, the more energy will be lost while doing so.

One problem however is that only a fool would use hardmetal bullets in a pistol, as pistols are generally used at shorter range, and hardmetal bullets hitting metal can ricochet straight back at you with anything up to deadly results.

You can of course use a soft bullet with a penetrator core or hardmetal jacket, but these have their own downsides, and the described effect effectively precludes such except possibly hardmetal jacket at least.

The serious problem is that to penetrate 2 breastplates and then still have the energy to completely smash up wood as well, you frankly need a crapload of energy.

jtg452 wrote:Add to all of that the fact that the bullet in question is designed to be fired at a much higher velocity. The M96 round is designed to work at 1600+ fps. To push a lead bullet that fast, the lead alloy used to make the projectile must be harder and there is a mention in the text of them quenching the bullets to increase the hardness as well.

1600fps is nothing extreme. The good old 1905 Mauser has a V0 at 2600-2700fps.

For a real world comparison using a lead bullet(with steel jacket) to PUNCH through armour by raw force:
https://en.wikipedia.org/wiki/Karabin_p ... erny_wz.35
It needed a velocity of over 4000fps to do that effectively however.

At that point you start getting some degree of fluid mechanics replacing penetration as normally computed, the same way as modern tank gun HVAPFSDS penetrators punch through armour mostly by fluid mechanics.

jtg452 wrote:So we have a bullet that is as hard or (probably) harder than a modern round that has been seen by first hand witnesses performing, that weighs twice as much, going just as fast with a much smaller point of contact. I have no problem believing that it will perform just as advertised. The numbers are there.

I have trouble agreeing with that. The link above gives a hint of what is needed to punch through armour reliably with a partially soft bullet, and even if the stated breastplates top out at a paltry 3mm, which is unlikely in an environment where firearms have begun to be used, soft and slow bullets will still have issues punching through three separate objects.

jtg452 wrote:viewtopic.php?f=7&t=4850&p=117375#p117375

And as you will note, i was active in that thread as well.

jtg452 wrote:The M96 rifle round

Are you referring to the M896 from RFCs books, or the real world history M/96?

I presume the former but it is more than a little derailing when thrown around like this.
The M/96 used the 6.5x55 Mauser ammo and was in use from 1895 to 1995.

I've got a 458 winchester that I typically load with a 500 grain bullet (it is not a spitzer round think of something more like a 45-70). The round is is not solid lead, just full jacketed. The muzzle velocity is around 2000 feet per second with something like 4000 ft lbs of energy at 100 yards. Sounds like the kind of energy you need to poke through a breast plate.

If my memory serves me correctly the maximum penetration in flesh (say elephant or rhino) occurs around 1200 ft/sec and is around 4 feet or so. Other than the fact the recoil is terrible, and as a black powder weapon the smoke would cover a fair size metropolitan area its a good hunting weapon

Tenshinai wrote:
And there was a criminal in Australia early 20th century who made himself an armour that covered him almost completely, and then "went to town", the police used up hordes of bullets before taking him down, by shooting at the soles of his feet as he walked. Those were the only places his armour couldn´t prevent the bullets from causing real harm.

Ned's armor weighed in at 44kg (97lb) and was made from plow blades. He was brought down with shots to the lower legs (not feet) after he came back behind the attacking troopers after escaping the initial attack. (You don't wear 44 kilos on a route march). Breast plates rather went out of favor with the invention of the rifle as they were usually made from wrought iron (not good manganese steel) and were no match for a 50 caliber minie ball.