Originally posted by Old Marksman
Quote:
However, you previously pointed out that there is no consensus as to why, or even if, one caliber is more effective than another.
More accurately, John pointed out that the best judgment today is that within the range of premium law enforcement cartridgedes from 9mm to .45, there is no significant difference in terms of terminal ballistics.
John used the term "typical service pistol caliber cartridges".
That most obviously not mean that a 2mm Kolibri pinfire would not be much, much less effective.
And I addressed this in my previous response to John. John said that .380/9mm is the dividing line because below 9mm you can't get adequate penetration with expanding bullets. However, John also said this in post # 95:
Originally posted by JohnKSa
Unfortunately it's even more difficult to quantify terminal effect in terms of actual stopping power/incapacitation time/incapacitation probability/etc. So difficult, in fact, that no one has managed to come up with an accepted method in decades of trying. Various people measure diameter, energy, momentum, power factor, penetration, wound volume, etc., and endlessly argue why one parameter is better than another one for predicting effectiveness. But when you ask them what the measured differences will mean in terms of how much faster someone hit solidly will stop shooting at you, or how many fewer shots it will take to incapacitate someone using a caliber that scores higher things get very quiet.
emphasis added
So if, as John pointed out, none of the above mentioned measurements is a reliable predictor of terminal effectiveness, then we cannot predict how much better a 9mm which penetrates 12+" is than a .380 which penetrates 10". Likewise, we cannot predict how much better a 9mm which expands to .55" is vs. a .380 which does not expand. Sure, we know that the 9mm is
probably somewhat better, but we don't know how much. That leads us into this statement from post # 112
Originally posted by JohnKSa
In light of that, which makes more sense? Does it make more sense to point out that if there is a difference no one has been able to demonstrate it and therefore it would be prudent to be skeptical about the practical value of such a difference, if it exists? Or is it wiser to claim that there’s obviously a practical difference even though no one can prove it?
So, if the fact that a 10mm rates above a 9mm in every way that anyone has come up with to measure terminal effectiveness is outweighed by the 9mm's lower recoil because none of the measures of terminal effectiveness are reliable, then I fail to see why those same unreliable measures of terminal effectiveness outweigh the even lower recoil of a .380. I'm sorry but you can't tell me that every measure of terminal effectiveness that we've come up with is unreliable and then turn around a use one or two of those same measures (penetration and wound volume) to justify why your preferred cartridge is better than another.
Originally posted by Old Marksman
One more time, John repeated findings from qualified experts that within a range, differences in wound volume are insignificant.
He did not say that substantially greater wound volume would not offer an advantage.
Of course, with it comes disadvantages.
Originally posted by Old Marksman
I have heard that some cartridges do not measure up in terms of penetration and permanent wound channel.
Well then let's look at some wound volume and penetration numbers for "premium law enforcement" ammo. We can fairly easily calculate approximate wound volume by simply multiplying the frontal area of the bullet by its penetration depth, so from Brassfetcher's bare 10% gelatin tests we get the following:
.380 ACP Winchester 95 gr Ranger-T: 9.3" penetration, 0.259 sq. " expansion, 2.41 sq. " total wound volume
9mm Winchester 127 gr +P+ Ranger-T: 11.2" penetration, 0.323 sq. " expansion, 3.62 sq. " total wound volume
.45 ACP Winchester 230 gr +P Ranger-T: 13.3" penetration, 0.471 sq. " expansion, 6.26 sq. " total wound volume.
So, the difference in total wound volume between the .380 and 9mm (in a +P+ loading no less) is 1.21 sq. ". That means, according to your own statements, that 1.21 sq. " is the difference between adequate and inadequate. However, the difference between the 9mm and the .45 ACP is 2.64 sq. ", over twice the difference between the 9mm and .380.
So, please explain to me why a .380 is inadequate when, by the numbers, it performs much closer to the 9mm than the .45 which you say does not offer enough increased terminal effect to be worth the extra recoil. It would seem to me that if, as you contend, the increased wound volume of the .45 isn't worth the extra recoil over the 9mm, then the even smaller difference between the 9mm and .380 wound volume should be outweighed by the .380's lighter recoil.
Originally posted by Old Marksman
Do you disagree that there is a desirable minimum in terms of penetration, and that, all other things being equal, a larger permanent wound channel is better than a smaller one?
But all things are never equal, and the rate of combat accurate shooting becomes important for increasing the likelihood of hitting something critical. Defensive shooters are not attacked by water jugs.
I don't disagree that there is a desirable minimum in penetration, but not everyone agrees on exactly what that desirable minimum is. I have read some rather compelling arguments as to why as little as 10" is a sufficient minimum and I have read other equally compelling arguments as to why as much as 16" should be the sufficient minimum.
Even the FBI does not pin penetration down to one magic number. In
Handgun Wounding Factors and Effectiveness, Patrick Urey makes the following statement:
While penetration of up to 18 inches is preferable, a handgun bullet MUST penetrate 12 inches of soft body tissue at a minimum, regardless of whether it expands or not.
emphasis added
http://firearmstactical.com/pdf/fbi-hwfe.pdf
Now perhaps you interpret that statement differently than I do, but it sounds to me that the FBI is saying that a bullet that penetrates 18" is better than one which penetrates 12".
Originally posted by Old Marksman
But there are some very good reasons why law enforcement officers rarely carry the 10mm. .41 Magnum, or .44 Magnum on duty.
Choosing a gun for an entire police department and choosing one for yourself are two very different things. A department of significant size is going to have officers of varying, size, strength, skill level, and experience. Some of the officers may very well be able to shoot a 10mm, .41 Magnum, or .44 Magnum adequately, but others may not. In such a case, it is prudent to find the combination of gun, caliber, and ammunition that
everyone in the department can shoot adequately. Likewise, large calibers, more often than not, come in large guns with large grips. Some officers may have smaller hands and thus it makes sense to choose the gun/caliber which can fit the widest variety of hand sizes/shapes well.
I, however, don't have to find a single gun and caliber that a wide variety of people can shoot adequately, just one that
I can shoot adequately. It makes no difference if someone else can't shoot my 10mm, .41 Magnum, or .44 Magnum well, because he/she isn't the one who may have to use it. Too many people get caught up in what the police use and assume that what's best for a cop is best for everyone. They never stop to think that the needs/limitations of a cop's gun and the needs/limitations of a private individual's gun are not always one in the same.