For self defense compact carry (less than 4 inch barrel), what are the proven advantages between Hornady Critical Defense (CD) and Corbon DPX?
From my reading it seems DPX for hard barrier, CD for heavy clothing but not hard barrier. But wouldn’t DPX have problems plugging/expanding since it has a pluggable hollow point?
I’ve also read CD was specifically designed for short barrels. Not sure what that means.
And since this is for self defense, not LE, I don’t see and high probability of legal scenarios with me shooting through hard barriers to defend myself. So not interested in windshield, plywood, metal, or other hard barriers. The barrier I’m most interested is heavy winter clothing.
It’s interesting that you say that about the DPX (using the Barnes SCHP XPB bullet), since every test I’ve seen from Doc Roberts and others shows the round to penetrate excellently through all the barriers presented by the FBI tests. Do you have any data showing this not to be the case?
I personally don’t put much stock in water tests. If it was an effective test the FBI and other LEO would make it a test protocol.
That said, I would take DPX over CD. The CD I’ve seen chronoed were much lower than advertised and I have seen feeding problems with them in several pistols (Gen. 3 Glocks, M&P, etc.)
Personally I was underwhelmed by CD. Would much rather have DPX, Federal HST, or Speer GD.
I personally don’t put much stock in water tests. If it was an effective test the FBI and other LEO would make it a test protocol.
Water is a valid medium to test for bullet expansion.
Whereas penetration depth in soft tissues or a realistic soft tissue simulant can be reasonably estimated using water as a test medium. It isn’t as precise as ordnance gelatin. See “Estimating Handgun Hollowpoint Bullet Penetration Using the MacPherson Water Test Method” at: http://www.firearmstactical.com/briefs5.htm
In the last issue of Wound Ballistics Review (Vol. 5 No. 2), Fackler presented a paper titled “Simplified Bullet Effect Testing”, in which the abstract states:
PURPOSE: To describe a simple and inexpensive test for handgun bullet performance.
METHOD: Bullets are fired through a single half-gallon cardboard milk carton filled with water, backed by a twenty-six-inch-long cardboard box filled with unspun cotton fibers.
RESULTS: The four inches of water causes a handgun bullet to expand as it does in living tissue. The cotton fiber material wraps around the bullet and stops it for recovery while causing it no additional deformity.
CONCLUSION: The resistance to a bullet’s penetration in water mimics closely the deformation-causing potential in living soft-tissue. Unspun cotton fibers capture a bullet without causing it to deform or fragment. Since the cotton can be reused indefinitely, only a single one-half gallon milk carton needs to be replaced for each new shot.
Paragraph 2 of Fackler’s paper states:
Shots into water cause bullet to expand as they do in gelatin or muscle.(1) Water-filled tanks are used almost universally for recovering test bullet in criminalistics laboratories. We have published an article describing a method for shooting into a homemade water tank.(2) In general, however, water tanks are expensive and bulky, and tanks are justified only where a lot of bullet testing is done. In 1990, IWBA member Gus Cotey published an article describing a “poor man’s ballistics lab” in which he fired into lined-up water-filled cardboard milk or juice cartons.(3) More recently, Gus published a follow-up article describing the limitations of water-filled cartons in predicting bullet penetration.(4) Another recent article, in which water-filled cartons were used to test rifle bullets,(5) illustrated the inconvenience of having to use up to 16 cartons to assure capturing the test bullet.
[ol]
[li]Facker ML. Police Handgun Ammunition Selection. Wound Ballistics Rev, 1992;1(3):32-37
[/li]> [li]Jones RL. Water Testing .38 Special +P Hollow Points. Wound Ballistics Rev, 1997;3(1):13-16
[/li]> [li]Cotey G. A poor man’s ballistics lab. Rifle, 1990;128:18-21&43
[/li]> [li]Cotey G. The Limitations of Water-filled Cardboard Cartons in Predicting Bullet Penetration. Wound Ballistics Rev, 1999;4(1):30-35
[/li]> [li]Hagen M. 5.45x39 MM JHP Ammunition for the AK-74. Wound Ballistics Rev, 2001;5(1)17-22
[/li]> [/ol]
I’ve been wanting to perform comparative testing of ordnance gelatin and then using the same ammunition using Fackler’s “Simplified Bullet Effect Testing” to compare and validate expansion and penetration/estimated penetration results from both methods.
Water testing can reveal the absolute best expansion a projectile is likely to offer; it does not provide the optimal assessment format for determining intermediate barrier performance and other less ideal parameters of terminal effects.
Within the same caliber, and when compared to standard factory JHPs, I have found the DPX type bullets to be the very best available at getting though hard barriers like car body sheet metal.
True, however steel barriers are typically hard on projectiles. Most that are put against steel, “soft” or not, will tend to crush and not expand, or fragment and fail to penetrate. Even the best loads available are basically wadcutters when the barrier is through with them.
Others have done great testing, and continue to. Steel barriers are part of the fbi’s protocol, and most everyone who tests against it tests against sheet metal as an intermediate barrier.
And, why test, if not to seek to expand knowledge?
We know through repeated study and comparison with the real world a set of basic parameters gauging effectiveness of loads in the real world correlated with outcomes of tests in a lab setting using 10% ordnance gel.
The FBI protocol is an accepted standard used by law enforcement and military to test bullet performance using 10% ordnance gel combined with common intermediate barriers such as wall board, heavy clothing, car door steel, and auto glass.
Doctor Gary Roberts, our very own DocGKR, is a professional of military and medical background who has, for the past twenty-some years, studied the topic and is considered by the Military, FBI and others to be an expert on the topic. He and his crew perform research and testing of bullets using the FBI protocol tests, and his data is readily available here and elsewhere.
Dr. Martin Fackler, another person with a medical background and who is respected as well as an expert on the subject, has done likewise in terms of testing and has quite a few excellent papers available discussing the results.
What do they test? Whatever they are called upon to test. Mainly they test loads of law enforcement interest (and consequently of personal defense carry interest), but he also tests ammunition submitted by individuals.
As to my statement about why we test…it was in reference to your statement that adding steel or such would “change the testing up drastically”. Basically, we have an established set of tests performed by individuals, law enforcement institutions, and government agencies (both law enforcement and military, as well as research), which includes testing out every possible circumstance people can think of to vette new loads, as well as to check existing loads as nes requirements are introduced.
Changing up testing is, to me, no great concern as to me, testing of hypothesis or materials is all a part of expanding knowledge and learning. That’s why, I presume, most of us do what we do. We ask questions, we verify results, and we conduct tests in order to ascertain the truth and learn new things. And we come here to share our thoughts and data with others so that we can learn and expand beyound our own set of circumstances. That’s all.
Its hard compared to most bullets launched at it, and to the other barriers in the FBI testing such as plywood, and in layers will stop many handgun bullets.
I recall a test where two sheets of 16 gauge sheet metal was used instead of the standard (IIRC) 20 gauge. The 9mm DPX only penetrated 7" in gelatin after that barrier, which isn’t that impressive, until you find that every other 9mm JHP service style ammo tested failed to get through the second sheet.
The DPX (Barnes TAC-XP) is the opposite of a “very soft” round; it’s actually a very hard round as copper is much, much harder than lead, and it will therefore penetrate barriers very well.