Winter defensive load - HP versus FMJ

[Mindflayer]

Reading gunderwood's post about the .357 SIG and penetration reminded me of a question. What do you load in your guns come winter?

I've read and listened to some experts weigh in and there appears to be a split in decision. Some recommend FMJ during the winter to reliably cut through all the extra layers of clothing. Some recommend using HP to ensure expansion, even if you may have some clogging or early expansion. Some recommend center-post (like Hydra-Shok) or polymer-tipped (Hornady Critical Defense or Corbon Pow’RBall).

It's getting colder, which means more cover, which means more chances to carry my .45 ACP with me. OTOH, since it's a slower round and according to the Internet Experts™ useless in winter, I may have to just carry my 9x19 with me.

Do you change your ammo in the winter? If so, to what, and why?

[Jakeiscrazy]

This site offer a lot of insight in to such internet rumors. Very goo IMO.
http://www.theboxotruth.com/docs/bot8.htm

[gunderwood]

No change.

If a HP clogs, then it doesn't expand and degrades to FMJ. In such cases, larger is definitely better IMHO. I think it is important to distinguish between soft tissue penetration and hard object penetration. I'm going to simply this, but...

For example, cartridges that are designed to penetration armor focus on small area and velocity. They defeat the armor by focusing the energy on a small area which causes the armor's bonds to essentially "break" at that localized area. Propel the projectile fast enough and you don't even need that hard of a projectile (or that heavy) to defeat serious armor. If you have ever seen a rail gun test, you know exactly what I mean. Energy is mass * velocity^2 (or mass * velocity * velocity). Clearly you gain more through high velocity than more mass.

Armor defeats projectiles in two ways. First, it generally works by absorbing and spreading the projectiles energy over a larger area. When ceramic armor fractures this is exactly what it is doing. Second, armor is usually designed to be very hard (AR500 steel, ceramics, etc.) so that it can shatter the projectiles penetrator. The idea is that you turn the energy in the penetrator against its self. Shattering a penetrator uses up a lot of energy. Also, it goes without saying that the remaining energy is no longer focused on a small area.

Try this thought out. Most LE wear Level II-A vests which are capable of stopping virtually any handgun threat (IIRC the new NIST standard uses the 125gr .357SIG for penetration tests and 180gr 40SW for blunt trauma). The Kevlar (or similar) works by spreading the load out. Bigger/heavier rounds posse very little penetration threat, but they are potentially a serious problem for blunt trauma as the body still absorbs a lot. Level II-A will stop 9mm out of a handgun, but not out of a SMG (technically it might, but it isn't tested for such until III-A). Same round, same weight, but just more velocity. Rifles go through soft armor like butter. Again, the idea is that you defeat the armor by dumping a lot of energy in a small area and simply overwhelm the local bonds.

Explosively Form Projectiles, do the same thing. The explosive doesn't defeat the armor, it is the liquid material (usually copper) moving at high velocities that is focused on an area about the size of a pencil which defeats the armor. Cages and reactive armor defeat this threat because they disrupt that stream. The EFP stream has very high energy, but very little momentum by comparison. If you spread it out even a little bit it doesn't do jack diddle.

On the other hand, momentum is much more useful for deep penetration of softer materials. This is why we have the general rule of thumb that "heavier" rounds penetrate more. Momentum is mass * velocity. No advantage to upping velocity vs increasing the mass (units matter, but roll with it). Taken from the Wikipedia momentum page:

According to Newton's second law, the rate of change of the momentum of a particle is proportional to the resultant force acting on the particle and is in the direction of that force.
http://en.wikipedia.org/wiki/Momentum#R ... d_velocity

I.e. the more momentum something has, the more force that must "push" against it to bring that velocity to zero. In layman's terms, the more momentum, the more stuff it can push aside before stopping. It should be apparent that larger calibers have to push aside more "stuff" for the same penetration. Assuming no expansion a rough estimate says that a .45 pushes aside approx. 1.6x as much stuff as a 9mm. In order to penetrate the to the same depth, the .45 needs approx. 1.6x as much momentum.

I'm grossly over simplifying it, but you get the drift. Harder objects like metal and glass favor "velocity penetration" (assuming the projectile stays intact more or less), while softer materials "momentum penetration." The problem with leather and skin is that they are very elastic and spread the loading out. Not to the extent Kevlar does, but skin is worth a good inch or two of gel. I need to look this back up as I don't recall the actual estimates, but this supports the point:

Also, skin is elastic and tough enough to cause a bullet to be retained in the body, even if the bullet had a relatively high velocity when it hit the skin. About 250 ft/s (76 m/s) velocity is required for an expanded hollow point bullet to puncture skin 50% of the time.

Personally, I just use good HPs and don't worry about it. While caliber wars are fun at times, the reality is that with modern HPs the four common calibers (9mm/357SIG/40SW/.45ACP) are very close. Some calibers are slightly better at certain things or more precisely certain tests, but shot placement always matters more.

[gunderwood]

This site offer a lot of insight in to such internet rumors. Very goo IMO.
http://www.theboxotruth.com/docs/bot8.htm

The box of truth is neat, but their testing isn't very scientific. For example, the denim isn't up against a soft tissue like you commonly find when someone is wearing it. That causes all kinds of problems. Case in point, it is a little known fact that most soft bullet proof vests aren't bullet proof on their own. I.e. they require the support of a human body as part of their "structure." Even with a bullet proof vest on, if you get shot, it is going to hurt and you are going to end up with a real nice bruise.

[Jim]

If I had to resort to deadly force for self defense, I would be using my .45 auto. I only carry my Judge when I'm in a situation where I might encounter Mr. Wiggly. My auto is loaded with stock factory mfgr'd. FMJ rounds. I feel very confident that I could, at least, stop the threat with such a load, even if the assailant were clothed heavily.
However(comma) I do carry my Judge from time to time "in the street". That is always loaded with Sierra 230 gr. JHPs over 5 gr. of Bullseye. Again, I feel confident I could stop a threat with that combination.
I'm not a professional ballistician and I have never tested my handloads, but I do believe there is an element to being confidant in your sidearm and what you carry in it. If I had any doubt or suspicion that my equipment is not suitable, I would certainly make the necessary changes.

[ProShooter]

HP's are for self defense.

FMJ's are for target shooting.

stick with that and you'll be fine.

[gunderwood]

However(comma) I do carry my Judge from time to time "in the street". That is always loaded with Sierra 230 gr. JHPs over 5 gr. of Bullseye.

It is your call, but conventional wisdom says that you shouldn't use handloads for self defense. While handloading is well understood by gun owners, or at least respected, that is not true with the general public. It is not below the media or a prosecutor to make something of nothing. I.e. your handloads are more "deadly" or you loaded up killer rounds vice defensive rounds, etc. There is no validity to those sorts of arguments, but better safe than sorry IMHO.

[SgtBill]

I have to agree with Gunderwood on the above. I use all hollow point ammo that I reload to factory spec,s for both me and my wife to practice with. I also still stand on the fact of practicing the double or triple tap method of shooting. One or two in the chest and one in the head it won't matter what your chest shot's do in heavy clothing if they are hollowpoint's if the last shot is a head shot with proper placement. Your bad guy will go down.
Bill

[SgtBill]

However(comma) I do carry my Judge from time to time "in the street". That is always loaded with Sierra 230 gr. JHPs over 5 gr. of Bullseye.

It is your call, but conventional wisdom says that you shouldn't use handloads for self defense. While handloading is well understood by gun owners, or at least respected, that is not true with the general public. It is not below the media or a prosecutor to make something of nothing. I.e. your handloads are more "deadly" or you loaded up killer rounds vice defensive rounds, etc. There is no validity to those sorts of arguments, but better safe than sorry IMHO.

I agree 100% I use my handloads for practice but only carry factory Speer Gold Dot's.
Bill

[Jim]

There was an extensive thread on Cast Boolits forum some time back about the use of handloads for self defense. No one was able to produce any data showing that handloads have ever been brought up in a court case involving the use of such in self defense.
The idea that this could be a determining factor originated from a book written by Massad Ayoob. Multiple attempts were made to contact him concerning this and no one was able to get him to reply.
To date, the fact that handloads used in self defense could cause legal problems has not been proven.

[gunderwood]

There was an extensive thread on Cast Boolits forum some time back about the use of handloads for self defense. No one was able to produce any data showing that handloads have ever been brought up in a court case involving the use of such in self defense.
The idea that this could be a determining factor originated from a book written by Massad Ayoob. Multiple attempts were made to contact him concerning this and no one was able to get him to reply.
To date, the fact that handloads used in self defense could cause legal problems has not been proven.

AFAIK, you are correct. I know of no case where the use of handloads was an issue. That is why I phrased the reply as I did.

For me personally, I choose factory loads for several reasons. First, the potential legal issue as noted above. Second, factory SD loads usually have flash suppressants, which can be very hard or impossible to replicate with handloads. Third, factory SD loads usually have sealed primers, etc. I realize you can do this yourself, but I've never tested or compared the two to know if my sealants/processes are as good or better. Lastly, SD factory loads go through all kinds of testing. High temps to test safe pressures after the gun/ammo sits in a hot car. Cold temps too. A multitude of firearms, etc.

[zephyp]

Why use hand loads or your own cast bullets for SD and take even a small chance that some twit prosecutor might use it against you...ammo is not that expensive. Use your reloads on the range or for hunting.

[SELFDEFENSE]

HP's are for self defense.

FMJ's are for target shooting.

stick with that and you'll be fine.

+1

[jrswanson1]

If you're that concerned about it, use JHPs that are truncated cone shaped. If the hollow point gets plugged up, it will act like a semi-wadcutter and not like the goofy round nosed FMJs they insist on making for 9mms and 45 ACPs.

Jim