'Shotguns have dkb/dbt' - where did that myth (?) come from? - Page 2

Kromm · 12-07-2009, 12:26 PM

Usual estimates for punches assume about 1/6 the striker's mass, if the striker is leaning into the blow. Good punches aren't "whip cracks" that channel tons of energy into a hand. Good punches are closer to battering rams that have the entire arm, shoulder, and upper quarter of the torso behind them. An uppercut can do significantly better.

vicky_molokh · 12-07-2009, 12:37 PM

Quote:

Originally Posted by Kromm

Usual estimates for punches assume about 1/6 the striker's mass, if the striker is leaning into the blow. Good punches aren't "whip cracks" that channel tons of energy into a hand. Good punches are closer to battering rams that have the entire arm, shoulder, and upper quarter of the torso behind them. An uppercut can do significantly better.

What would be the in-game difference between the two? One as a Defensive Attack or what?

HANZO · 12-07-2009, 12:39 PM

There have been many cases of police or other law enforcement getting hit multiple times in a vest and having to be treated for internal bleeding from the impact of a hand gun at close range. as well as cracked ribs and a lot of bruising.

I think the myth is that wearing a vest allows the wearer to just keep taking hits like he is superman.

But then again look at the bank robbery in Hollywood a few years back. guys with layered heavy armor. Video

Then again this was what allowed the police there to start carrying AR-15s.

Anthony · 12-07-2009, 12:45 PM

Quote:

Originally Posted by Kromm

Good punches aren't "whip cracks" that channel tons of energy into a hand. Good punches are closer to battering rams that have the entire arm, shoulder, and upper quarter of the torso behind them.

In that case, reduce the '7 m/s' figure to 2-3 m/s, since your torso velocity is going to be around your step velocity and your shoulder velocity isn't going to be dramatically higher. There's a lot of options for how the energy is delivered, but the total impact energy is going to be in the 25-50J range for an average person.

vicky_molokh · 12-07-2009, 12:51 PM

Quote:

Originally Posted by HANZO

There have been many cases of police or other law enforcement getting hit multiple times in a vest and having to be treated for internal bleeding from the impact of a hand gun at close range. as well as cracked ribs and a lot of bruising.

I think the myth is that wearing a vest allows the wearer to just keep taking hits like he is superman.

But then again look at the bank robbery in Hollywood a few years back. guys with layered heavy armor. Video

Then again this was what allowed the police there to start carrying AR-15s.

Um, I'm not expecting the bulletproof vest to be bulletproof. But there seems to be an opinion that shotguns do 90% of their damage without penetrating the vest at all through the sheer 'crush' (against which vests supposedly offer no meaningful protection), unlike single-ball weapons which do most of their damage through penetration or 'pierce' (to use GURPS terminology).

vicky_molokh · 12-07-2009, 12:52 PM

Quote:

Originally Posted by Anthony

In that case, reduce the '7 m/s' figure to 2-3 m/s, since your torso velocity is going to be around your step velocity and your shoulder velocity isn't going to be dramatically higher. There's a lot of options for how the energy is delivered, but the total impact energy is going to be in the 25-50J range for an average person.

Wrong again, I think. There's step velocity, relative to which there is the relative torso velocity, relative to which is the relative arm velocity. It all adds up.

Kromm · 12-07-2009, 12:55 PM

Quote:

Originally Posted by Anthony

In that case, reduce the '7 m/s' figure to 2-3 m/s, since your torso velocity is going to be around your step velocity and your shoulder velocity isn't going to be dramatically higher. There's a lot of options for how the energy is delivered, but the total impact energy is going to be in the 25-50J range for an average person.

I don't disagree. What's important is really more the momentum difference . . . 1 kg at 7 m/s is 7 kg-m/s, while closer to 12 kg at 2 to 3 m/s is 24 to 36 kg-m/s, which is enough to make a 72-kg man stumble. A significant part of the self-defense value of a well-thrown punch is that it pushes the assailant away, regardless of whether it hurts him.

Lord Carnifex · 12-07-2009, 01:30 PM

Also to be remembered is that knock back is a phenomenon that emerges out of the attacker being well anchored vs. a target who is not. Although conservation of momentum and Newton's laws apply, a good punch, kick, or shotgun blast will typically come from someone who is expecting the momentum and whose center of gravity is placed over their foot (feet) and whose body is braced to absorb the momentum of the attack. Meanwhile, the target is not necessarily prepped to receive the jolt of momentum, and so can be knocked down or back because of it.

I've seen Muay Thai and Savate kicks that can accomplish quite a bit of knockback. I can only assume that a shotgun might be able to accomplish similar momentum.

Icelander · 12-07-2009, 01:39 PM

Quote:

Originally Posted by Molokh

Um, I'm not expecting the bulletproof vest to be bulletproof. But there seems to be an opinion that shotguns do 90% of their damage without penetrating the vest at all through the sheer 'crush' (against which vests supposedly offer no meaningful protection), unlike single-ball weapons which do most of their damage through penetration or 'pierce' (to use GURPS terminology).

Opinions are like fundamental orifices. Everyone's got one.

That doesn't change the fact that a ball of roughly .33 caliber travelling at low pistol speeds will perform poorly against body armour. And adding eight more similar balls won't magically make any of them perform better (and the odds of them impacting at precisely the same spot are minimal).

A tactical vest that's proofed against 9mm will also protect against anything up to triple-ought buckshot. Depending on design, it may leave broken ribs or it may be difficult to even notice during an adrenaline-charged encounter. Needless to say, vests of the former design will have a poor reputation with actual operators and will usually not be issued to police or military.

SimonAce · 12-07-2009, 04:20 PM

A shotgun slug is nearly an ounce of metal traveling at the speed of sound or faster. That might break ribs, might.

try this link, box of truth to see what 12g vs 3a vest is like

That doesn't mean the guy on the receiving end of things will even feel it to till the fights over though. buckshot won't go through soft armor or do the job well.

12-07-2009, 12:26 PM	#11
Kromm *GURPS* Line Editor Join Date: Jul 2004 Location: Montréal, Québec	Re: 'Shotguns have dkb/dbt' - where did that myth (?) come from? Usual estimates for punches assume about 1/6 the striker's mass, if the striker is leaning into the blow. Good punches aren't "whip cracks" that channel tons of energy into a hand. Good punches are closer to battering rams that have the entire arm, shoulder, and upper quarter of the torso behind them. An uppercut can do significantly better. __________________ Sean "Dr. Kromm" Punch <kromm@sjgames.com> *GURPS* Line Editor, Steve Jackson Games My DreamWidth [Just *GURPS* News]

12-07-2009, 12:39 PM	#13
HANZO Join Date: Feb 2005 Location: Washington state	Re: 'Shotguns have dkb/dbt' - where did that myth (?) come from? There have been many cases of police or other law enforcement getting hit multiple times in a vest and having to be treated for internal bleeding from the impact of a hand gun at close range. as well as cracked ribs and a lot of bruising. I think the myth is that wearing a vest allows the wearer to just keep taking hits like he is superman. But then again look at the bank robbery in Hollywood a few years back. guys with layered heavy armor. Video Then again this was what allowed the police there to start carrying AR-15s. __________________ Role-players are the only people I know that get away with bragging about the things they pretend they did.

12-07-2009, 01:30 PM	#18
Lord Carnifex Join Date: Oct 2005	Re: 'Shotguns have dkb/dbt' - where did that myth (?) come from? Also to be remembered is that knock back is a phenomenon that emerges out of the attacker being well anchored vs. a target who is not. Although conservation of momentum and Newton's laws apply, a good punch, kick, or shotgun blast will typically come from someone who is expecting the momentum and whose center of gravity is placed over their foot (feet) and whose body is braced to absorb the momentum of the attack. Meanwhile, the target is not necessarily prepped to receive the jolt of momentum, and so can be knocked down or back because of it. I've seen Muay Thai and Savate kicks that can accomplish quite a bit of knockback. I can only assume that a shotgun might be able to accomplish similar momentum. __________________ An ongoing narrative of philosophy, psychology, and semiotics: Et in Arcadia Ego "To an Irishman, a serious matter is a joke, and a joke is a serious matter."

12-07-2009, 04:20 PM	#20
SimonAce Join Date: Aug 2004	Re: 'Shotguns have dkb/dbt' - where did that myth (?) come from? A shotgun slug is nearly an ounce of metal traveling at the speed of sound or faster. That might break ribs, might. try this link, box of truth to see what 12g vs 3a vest is like That doesn't mean the guy on the receiving end of things will even feel it to till the fights over though. buckshot won't go through soft armor or do the job well.