# Contact Shot



## Honduras2811 (Feb 21, 2015)

This is not a scenario I ever expect to be in, but . . .

Suppose that I have a Derringer pressed against someone's head and fire. Is there any possibility that the pressure in the barrel will build up high enough to do damage to it?


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## TurboHonda (Aug 4, 2012)

I suppose if there was no hair at the point of contact and you was really holding a lot of pressure, then it could conceivably be an unusual pressure situation (much like an obstruction in the barrel). The possibility of damage to the gun could not be excluded. By the way, welcome to the forum.


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## SailDesign (Jul 17, 2014)

Any pressure high enough to damage the gun would also be enough to move the target or the gun-hand away enough to release it. No worries. 

And DON'T get into either end of that situation, 'K?

Welcome.


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## Thateus (Feb 12, 2015)

@ Honduras2811,

Your first post here and you are asking this. Are we contemplating suicide or killing spouse while they sleep ? 
Should we be concern enough.
Could be an innocent question just seems rather odd.


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## SouthernBoy (Jun 27, 2007)

I've seen color photos of contact handgun bullet wounds and what happens is the hot expanding gases from the burning powder follow the bullet into the initial wound channel. This creates a larger and uglier permanent wound channel and burns immediate tissues to some degree.

Here's some examples; *[WARNING: Sierra_Hunter reports that this link contains a virus]*

http://library.med.utah.edu/WebPath/FORHTML/FOR018.html
http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUN015.html
http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUN006.html


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## TurboHonda (Aug 4, 2012)

@Thateus

Com'on now. You, of all people, are suspicious of the unorthodox subject of someone's first post?


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## Thateus (Feb 12, 2015)

Only in the context of my superior knowledge of psychology.
My real name is Dr. Hackenbush
How would we feel if we found out this poster committed an unspeakable tragedy. Or if we learn he was sent to gather information about our true motives here.


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## pic (Nov 14, 2009)

Honduras2811 said:


> This is not a scenario I ever expect to be in, but . . .
> 
> Suppose that I have a Derringer pressed against someone's head and fire. Is there any possibility that the pressure in the barrel will build up high enough to do damage to it?


It's very possible .


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## TurboHonda (Aug 4, 2012)

Thateus said:


> Only in the context of my superior knowledge of psychology.
> My real name is Dr. Hackenbush
> How would we feel if we found out this poster committed an unspeakable tragedy. Or if we learn he was sent to gather information about our true motives here.


On the other hand, what if we learned that a tragedy was postponed or averted due to the OP's legitimate concern for damage to an expensive derringer?

As far as him being "sent" here, I seriously doubt that. After all, he/she went through the same rigorous acceptance procedures as you and me.


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## Thateus (Feb 12, 2015)

That's good enough for me.


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## Sierra_Hunter (Feb 17, 2015)

He said right in the too of the post it's not something he expects to happen. Sounds like a honest question to me. 

I would say the answer is yes. I had a junker contender barrel once that I tried pressing up against a hay bale (I pushed in as hard as I could) and it did damage the end of the barrel some.


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## Sierra_Hunter (Feb 17, 2015)

SouthernBoy said:


> I've seen color photos of contact handgun bullet wounds and what happens is the hot expanding gases from the burning powder follow the bullet into the initial wound channel. This creates larger and uglier permanent wound channel and burn immediate tissues to some degree.
> 
> Here's some examples;
> 
> ...


The link contains a virus. I can't open my browser without that image popping up constantly, and I havn't managed to figure out where it stored itself at to get rid of it. Just a warning to others thinking of viewing it...


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## SouthernBoy (Jun 27, 2007)

Sierra_Hunter said:


> The link contains a virus. I can't open my browser without that image popping up constantly, and I havn't managed to figure out where it stored itself at to get rid of it. Just a warning to others thinking of viewing it...


Thanks so much for posting this. I'll put a warning in my post and note your response accordingly.


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## Sierra_Hunter (Feb 17, 2015)

SouthernBoy said:


> Thanks so much for posting this. I'll put a warning in my post and note your response accordingly.


Not a problem. It did cause me some grief for a day or two but I got it fixed now.


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## Scorpion8 (Jan 29, 2011)

Seriously, I don't think you'd be able to keep the gun pressed so tight against the head that you'd be able to seal the barrel against the gas buildup pressure inside the barrel enough to do any damage.


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## SailDesign (Jul 17, 2014)

Scorpion8 said:


> Seriously, I don't think you'd be able to keep the gun pressed so tight against the head that you'd be able to seal the barrel against the gas buildup pressure inside the barrel enough to do any damage.


My point exactly. If you assume you can exert 100 lbs of force with your hand on the gun, then for a 22, the pressure required to push that away from whatever you're pressing on will be only 2,630 psi, given or take a couple. Interwebz search gives a value of twice that for "normal" 22?LR pressures.

For a 44, the pressure required is 4 times LESS...


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## TurboHonda (Aug 4, 2012)

SailDesign said:


> My point exactly. If you assume you can exert 100 lbs of force with your hand on the gun, then for a 22, the pressure required to push that away from whatever you're pressing on will be only 2,630 psi, given or take a couple. Interwebz search gives a value of twice that for "normal" 22?LR pressures.
> 
> For a 44, the pressure required is 4 times LESS...


Thanks for the calculations. You're helping prove my point. While the propellant is working to overcome pressure on the front side, it is building additional pressure on the back side. It is, in fact, a burning process affected by weight of the bullet, resistance to it's movement, and time.


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## SailDesign (Jul 17, 2014)

4 times less pressure means it is 4 times MORE LIKELY to "break the seal" I doubt anyone here can push hard enough to force a barrel to rupture. These are only push-away pressures. The max pressure allowed by a SAAMI .22 chamber is 10 times this - about 24,000 psi. You want to claim a 2000 lbs push with that right arm?


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## TurboHonda (Aug 4, 2012)

SailDesign said:


> 4 times less pressure means it is 4 times MORE LIKELY to "break the seal" I doubt anyone here can push hard enough to force a barrel to rupture. These are only push-away pressures. The max pressure allowed by a SAAMI .22 chamber is 10 times this - about 24,000 psi. You want to claim a 2000 lbs push with that right arm?


24,000 psi. OK. And how is that pressure achieved?

Oh! I know. The burning rate of the powder. The weight of the bullet. The resistance to it's movement. And time.

Find a good relaoading manual. Read and learn.


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## SailDesign (Jul 17, 2014)

TurboHonda said:


> 24,000 psi. OK. And how is that pressure achieved?
> 
> Oh! I know. The burning rate of the powder. The weight of the bullet. The resistance to it's movement. And time.
> 
> Find a good relaoading manual. Read and learn.


I know how it's achieved.... It is how it is applied to an un-fixed object that I'm interested in. You would have to push with a 2000 lb force to hold a 22 pistol against something hard enough that it wouldn't move away under the barrel pressure. If that "something was also unfixed, then you have no hope of holding it there hard enough to do any damage to the barrel.


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## TurboHonda (Aug 4, 2012)

SailDesign said:


> I know how it's achieved.... It is how it is applied to an un-fixed object that I'm interested in. You would have to push with a 2000 lb force to hold a 22 pistol against something hard enough that it wouldn't move away under the barrel pressure. If that "something was also unfixed, then you have no hope of holding it there hard enough to do any damage to the barrel.


OK. This will be it for me. No one said it WILL be damaged. I'm just saying that any obstruction of movement (RESISTANCE) will also add to the burning TIME, thereby adding to the PRESSURE. How much it adds I don't know. The manufacturer didn't go there and neither will I.


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## SailDesign (Jul 17, 2014)

TurboHonda said:


> OK. This will be it for me. No one said it WILL be damaged. I'm just saying that any obstruction of movement (RESISTANCE) will also add to the burning TIME, thereby adding to the PRESSURE. How much it adds I don't know. The manufacturer didn't go there and neither will I.


This will be it for me as well 

The original question was "will it damage the barrel" and my contention (disagree if you wish - no skin off my nose) is that you cannot press the barrel hard enough against something to allow the pressure to damage it, since the barrel is built (for a 22 - others are higher) to handle 10 times the pressure you could resist.


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## Scorpion8 (Jan 29, 2011)

Actually all it's going to take is a clump or hair or a crease of skin right where you have the barrel pressed and undoubtedly gases will escape thru that path-of-least-resistance. None of us have perfectly flat spots on our heads that would seal a barrel against those kinds of pressures with just hand pressure exerted to hold the barrel sealed.


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