I think he was asking about hard plate armour
I think he was asking about hard plate armour
It's not logic, it's physics. The total force felt in recoil of a single shot weapon is the same as the force of the projectile at the muzzle (minus some escaping gasses). The shooter feels this force over a tiny amount of extra time (time between powder ignition and the projectile leaving the muzzle) and over a larger surface area (various grips and the stock).
The receiver feels this force minus some air resistance nearly instantly, but spread over a large area (area of the plate). It likely will be noticed, but not likely cause any damage.
"I never learned from a man who agreed with me." Robert A. Heinlein
Back face signature. I do know of one case with a .44 mag pistol, death occurred although the vest(soft/no plate) did actually stop the projectile(trauma to the heart). Many factors are in play, caliber, vest type, location of strike and physical characteristics of the body.
GET IN YOUR BUBBLE!
This is a Protech Impac ST trauma plate that we shot during vest testing in 2009.
It was in front of a IIIA Xtreme Force soft vest mounted on Safariland's vest testing clay filled torso.
We shot it with 4 rds of 5.7x28 and then a 12 ga Rem reduced recoil 1oz slug (1131 fps).
ALL the deformation you see is from the slug. There was 34mm of BFS in the clay.
For comparison, the same slug shot into the vest alone (without the trauma plate), created a BFS of 44mm.
ImpactST003.jpg
Front w/mushroomed slug; 4 marks are where the 5.7's hit
ImpactST004.jpg
Side view showing deformation
ImpactST005.jpg
Back view (no penetrations)
ImpactST007.jpg
Mushroomed slug and one of the 5.7's
Last edited by smp444; 12-30-16 at 13:12.
Layer it up this way:
Wear a III+ hard plate
Behind it a III soft plate
Trauma pad behind that closest to body.
Still would hurt like a SOB, but you would come out of it alive.
Friend of mine took a 7.62 x 51 round right in the chest from about ten yards away, using what at the time was experimental ceramic plates. Said he took the hit, staggered into a house and collapsed. Woke up in hospital. Said it felt like somebody had swung a baseball bat as hard as they could right into his chest. Bruised ribs, caught some spall in the face. Lived to tell the story.
Physics is physics and the recoil force felt is not the same as the force acting on the projo that gets it up to speed. The weight/mass of the gun is a huge component. You can launch a 12 gauge slug from a 50 lb shotgun and you will feel effectively no recoil, but the forces that accelerated that slug in that short time to 1600 fps were the same, and the kinetic energy possessed by the slug at muzzle velocity is the same as if it was launched from a 5 pound single shot.
Kinetic Energy (ft-lb) [does not equal] Force (lb) [does not equal] momentum (pound feet per second).
People who have legit taken 5.56 and x39 rounds on a ceramic plate will tell you it hurts plenty, a slug won't be any better.
A plate doesn't "spread" the force of a projectile the way you think, they in fact become much less rigid when struck, although some of the newer stuff is getting much better.
We had a deputy take a 12 gauge slug to the trauma plate and he survived. He had a lot of damage and had a significant hole due to soft tissue damage to his upper chest. When they pulled the vacuume packing off him when we took him home you could see his ribs. After being shot he was able to return fire and wounded the suspect.
Dan
It's because the plate deforms. If the plate absorbed/bonded with the projectile and moved from the point of impact as a solid mass with no deformation, it would not cause damage. Like you said, when you shoot the gun, the guns mass changes things, and you have a shoulder and arms absorbing the recoil.
The plate will not deform equally in all directions to absorb the KE of the projectile. Their will be a significant difference between the point of impact and the outer edges of the plate. That should tell you that although it may stop the projectile, it is certainly not going to exactly and evenly distribute the force of the impact.
I believe that Deputy is one lucky fellow. The fact that he didn't die and was able to return fire says a lot of good about plates, but not everyone is going to be that lucky.
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