Bigger hole by bigger bullet diameter?

Para Bellum · December 28, 2005, 03:38 PM

If you read publications as the following:
http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

you might get the Idea that
- temporary cavity is nothing (?) because tissue is elastic and
- the bigger bullet makes the bigger hole (?)

IMHO these two statements are contradicting each other.
If tissue is so elastic that even a temporary cavity of several inches is nothing really then why should the difference in bullet diameter from .22 inches to .50 inches make any difference in the diameter of a permanent cavity at all?

Wouldn the elastic tissue stretch the same way around a .22 bullet then around a .50 bullet? Wouldn't the actual hole in the tissue be mininmal anyway?

mete · December 28, 2005, 06:06 PM

There is always some permanent cavity and the bigger the diameter the bigger the permanent cavity. Also bullet shape will effect the permanent cavity - a semi wadcutter will create a bigger hole than a round nose bullet. You should find something to shoot so you can see these things for yourself. Most of my tests have been on woodchucks [marmots] and feral dogs.

Mannlicher · December 28, 2005, 06:22 PM

My informal tests involve post mortems on game animals. I have to agree with mete, in that a larger diameter bullet seems to leave a larger area of meat damaged. I think that on small game, a really fast, small bullet would be devistating, but on deer and hogs, its the larger diameter bullets that seem to get the job done.

BigFunWMU · December 28, 2005, 06:29 PM

The fun thing is that the bullet is not just larger, its a lot faster too. Therefore there is a lot more energy passed in to "el Critter" to mess him up.

And doubling the diameter of the bullet gives 4x the cross section.

Weeg · December 29, 2005, 08:52 AM

The effects of the temporaty cavity depend on anatomic region as well

.

Mark54g · December 29, 2005, 08:56 AM

What I don't understand about this is that they assume that tissue elasticity is a constant and is also the same throughout different people and different tissue types. One of the very reasons, it seems, that rifles do so much more damage is that the temporary cavity stretches past the tissue's ability to remain elastic and it tears open. Getting these results with a handgun is not easy, but I am sure that the temporary cavity can induce tissue tearing as well. There is too much of this thought that things must be one or the other and not a combination of multiple factors. I would not rely on a round with JUST an impressive temporary cavity, but I do think it is a helpful thing to have.

Para Bellum · December 31, 2005, 04:39 AM

Quote:

There is always some permanent cavity and the bigger the diameter the bigger the permanent cavity.

I still doubt that with similar calibers. e.g. .223 FMJ vs .308 FMJ and 9x19mm FMJ vs. .45 FMJ.
With these calibers the bigger is slower and I'm not convinced that even with FMJs the bigger diameter makes the wider permanent cavity...

December 28, 2005, 03:38 PM	#1
Para Bellum Senior Member Join Date: January 7, 2005 Location: right there Posts: 1,882	Bigger hole by bigger bullet diameter? If you read publications as the following: http://www.firearmstactical.com/pdf/fbi-hwfe.pdf you might get the Idea that - temporary cavity is nothing (?) because tissue is elastic and - the bigger bullet makes the bigger hole (?) IMHO these two statements are contradicting each other. If tissue is so elastic that even a temporary cavity of several inches is nothing really then why should the difference in bullet diameter from .22 inches to .50 inches make any difference in the diameter of a permanent cavity at all? Wouldn the elastic tissue stretch the same way around a .22 bullet then around a .50 bullet? Wouldn't the actual hole in the tissue be mininmal anyway? __________________ Si vis pacem - para bellum If you want peace - prepare for war

December 28, 2005, 06:22 PM	#3
Mannlicher Senior Member Join Date: July 8, 2001 Location: North Central Florida & Miami Posts: 3,209	My informal tests involve post mortems on game animals. I have to agree with mete, in that a larger diameter bullet seems to leave a larger area of meat damaged. I think that on small game, a really fast, small bullet would be devistating, but on deer and hogs, its the larger diameter bullets that seem to get the job done. __________________ Nemo Me Impune Lacesset "The trouble with our liberal friends is not that they're ignorant; it's just that they know so much that isn't so.".........Ronald Reagan

December 28, 2005, 06:06 PM	#2
mete Senior Member Join Date: June 14, 2004 Location: NY State Posts: 6,575	There is always some permanent cavity and the bigger the diameter the bigger the permanent cavity. Also bullet shape will effect the permanent cavity - a semi wadcutter will create a bigger hole than a round nose bullet. You should find something to shoot so you can see these things for yourself. Most of my tests have been on woodchucks [marmots] and feral dogs.

December 28, 2005, 06:29 PM	#4
BigFunWMU Senior Member Join Date: April 26, 2005 Posts: 304	The fun thing is that the bullet is not just larger, its a lot faster too. Therefore there is a lot more energy passed in to "el Critter" to mess him up. And doubling the diameter of the bullet gives 4x the cross section.

December 29, 2005, 08:52 AM	#5
Weeg Senior Member Join Date: November 7, 2005 Posts: 463	The effects of the temporaty cavity depend on anatomic region as well .

December 29, 2005, 08:56 AM	#6
Mark54g Senior Member Join Date: March 21, 2005 Location: NJ Posts: 1,265	What I don't understand about this is that they assume that tissue elasticity is a constant and is also the same throughout different people and different tissue types. One of the very reasons, it seems, that rifles do so much more damage is that the temporary cavity stretches past the tissue's ability to remain elastic and it tears open. Getting these results with a handgun is not easy, but I am sure that the temporary cavity can induce tissue tearing as well. There is too much of this thought that things must be one or the other and not a combination of multiple factors. I would not rely on a round with JUST an impressive temporary cavity, but I do think it is a helpful thing to have.