.22 Pistols

Today let's talk about the lowly .22 pistol.  I say "lowly" only because no one considers this a suitable caliber for self-defense.  However, don't forget the first rule of gunfights, attributed to Col Jeff Cooper: bring a gun.  A .22 is always better than nothing, but just barely.  Yes, a .22 will kill a person, but usually only if you hit them in the head, neck, or femoral artery.  Hitting other places may do the job, but not quickly enough to save your life.  That said, if the pistol holds 10-15 rounds, I would be willing to stipulate that 8 or more fast shots on center mass is very likely to change the dynamic in the case of a home invasion, with only one or two assailants.

However, if a .22 pistol is small enough to carry concealed, it won't have enough ammo to help you much, and accuracy will be difficult (see Rule 1).  If all you can carry is a pocket gun, then get a .380.  Many people also consider the .380 to not have enough stopping power, but it is almost as powerful as a 9mm, and will clearly stop an attack if you have good shot placement, especially if loaded with +P ammo.  Yes, I know +P can wear out a .380 over time, but it won't hurt to use it for self-defense; just don't practice much with it.

So, for this discussion we've mostly eliminated the .22 from concealed carry (see Rule 1).  That leaves us with bigger guns, which are mostly target pistols. Competition target shooters will often spend big bucks on these, over $1000 for models from Walther, Hammerli, or Smith & Wesson, but there are some very nice models available for $300-500.  Two of the best known are the High Standard Sport King and the Browning Buck Mark, but I am going to write about two that I own: the Ruger Mark III 22/45, and the Colt 1911 (22).  Both are fairly heavy, have large capacity, and have long barrels; accuracy is quite good, and recoil almost non-existent.  Keep in mind that the kind of accuracy inherent with guns like these means hitting a 4 inch circle at 25 yards;  even a fairly new shooter could hit a person 10 times in a row at 7 yards.

Ruger Mark III 22/45
This is the newest version of a gun first produced in 1949, that popularized the .22 pistol.  The standard Mark III has a 60 degree grip angle, like a Luger, while the 22/45 version has a 75 degree grip angle, like a 1911.  They come with a fully adjustable rear sight, and threaded mounting holes for a rail (also included) for mounting a scope or red dot.  There are also many available accessories, like fiber optic front sights, competition triggers, springs, grips, etc.  You must get a speed-loader for it, as the magazines are difficult to load by hand.  Cleaning the gun is also difficult, as the break down process is complicated and frustrating.  Still, this is one of the most accurate and popular guns on the market, in its class. 

Colt 1911
This is not actually made by Colt, but by Walther in Germany, under license to Colt.  It is, however, absolutely identical to a Colt .45 1911, including the weight.  Many parts, like grips and springs, are interchangeable with real 1911 pistols.  It is a finely engineered handgun, equal in most ways to the Ruger, and better in some.  Disassembly and cleaning are very easy, and accuracy is very slightly better.  Walther makes two models of this gun: the Government Model (the more tradional M1A military style), and the Gold Cup (which has adjustable rear sights).  This model does come with a speed-loader.  I have the Government Model, but wish I had spent a little more for the Gold Cup, for the adjustable sights.  However, I am not unhappy at all with mine.  It is fun to shoot, and cycles the finicky .22 rounds perfectly.


There are other benefits to shooting a .22 target pistol:

1. Ammo is quite cheap, about 12-15 cents/round.  A few months ago it was hard to find, but the supply has recently caught up to demand. Don't buy the cheapest you can find, or subsonic, or high velocity (except for defensive purposes).  There is a substantial difference in accuracy between brands.  My favorites are Norma Target and CCI Standard Velocity.
2. They are very easy to shoot, so shooters can concentrate on technique without the fear of recoil getting in the way.  Many people actually have .22 conversion kits on high powered pistols and rifles, for inexpensive training.
3. Some people simply have a fear of guns that keeps them from trying to shoot, and would paralyze them in a crisis.  The .22 solves that.  It shoots like a BB gun.

In a perfect world, I would love to start all beginners on a .22 target pistol for a few weeks, then step up to a bigger caliber, but that is not practical.  It is a great way for people to get started with shooting, so if you have room in your budget for two or more guns, consider starting with a good .22 target pistol.

Don't forget Rule 1.

Oregon: active shooter on campus

Oct 1, 2015

As I write this, the news is aflame with the story of yet another mass shooting on a college campus.  The gun-grabbers wasted no time taking advantage of a crisis; within minutes, they were tweeting about the need for "common sense gun laws".  Indeed.  If we really had "common sense gun laws", there would have been several veterans on that campus with concealed handguns, and we would now be talking about 2 or 3 dead instead of 13.

Oregon already has laws against guns on campus, and the shooter was not eligible to possess a handgun, so what laws exactly do the "Moms" think would have prevented this crime?  The operative word here is "think", as their screed is just the usual knee-jerk reaction to any gun crime.

The real crime here, is called "gun-free zone".  John Lott, an economist with the Crime Prevention Research Center, has demonstrated that, since 1950, every mass shooting in America that took more than 3 lives (with one exception) has been committed in a gun free zone (schools, movie theaters, etc.).  This is just one more predictable example.  As I tell my classes, these people are crazy, but they are not stupid!

In 2012, one of those crazies, James Holmes, went into a movie theater in Aurora, CO, and killed 12 people.  He lived just a block from another theater, but it was NOT posted as off limits to guns.  Being not stupid, he went over a mile to the Century 16 theater, which WAS posted as off limits.  His was the biggest mass shooting in American history.  Until today.

Fourteen? Fifteen? Going once, going twice.  Sold, to the next crazy who wants to be famous. No one is safe, until we run out of gun free zones.

Ballistics 101

The average defensive handgun user doesn't spend much time reading about ballistics; it can be an arcane science, full of numbers, distances, and formulae.  It is, however, an important topic, and one that can save your life.

Any caliber of gun will kill, even a .22 if you hit the right spot.  That is not as important in defensive gun use as, will it stop the threat quickly?  Some years ago, a police officer was attacked by a felon with a large knife.  The cop shot him 6 times with a .38 Special.  The felon died, but lived long enough to get to the cop, and kill him.

The issue at hand here is not killing power, but stopping power.  That is a difficult metric to measure, but can be best expressed as energy transfer.

energy = mass x velocity

That is, given a constant speed, a larger (heavier) bullet creates more force, and greater stopping power, than a lighter bullet.  The problem is, heavier bullets require more powder to achieve the same speed (ignoring for the moment that hollow-points have greater wind resistance).  In fact, larger calibers do tend to use more powder to offset the greater weight, but there is a ceiling beyond which manufacturers cannot go and stay within established safety limits.

A lighter bullet traveling very fast can generate the same energy transfer as a heavier bullet going somewhat slower, but efficiency tapers off at both ends, creating what scientists call a "bell curve".  From a practical standpoint, this is complicated by the fact that larger caliber guns make rapid shooting more difficult, due to recoil affecting sight picture acquisition.  For that reason, the FBI stopped using 10mm handguns (which will kill a bear), and went back to the .45, and sometimes the .40.  Many police agencies have moved from the .45 all the way back to the 9mm.  Even though the 9mm generates less energy, follow-up shots are quicker and more accurate, and the guns typically carry more ammo, as much as 18 rounds.  No one is going to still be a threat after taking 10-18 bullets.  Recent ballistic tests have shown that 9mm +P ammo generates more energy than a .40 caliber. [+P are hotter factory loads]

The lesson there is, either carry bigger bullets, or more of them.

Much of the above, however, relates to full-size service pistols and home defense guns.  The person carrying a concealed weapon has to make allowance for the fact that most easily concealable guns will be smaller, lighter, or both.  That affects the ability to make rapid follow-up shots, similar to the 10mm problem, but on a smaller scale.  If that is not clear, try shooting a polymer snub-nosed .357 Magnum revolver.

A small .45 probably puts many people at a disadvantage, considering weight vs recoil.  Add 3 points for the greater energy of the bullets,  but subtract 1 point for the smaller round count.  An experienced, skilled shooter could make that work to his advantage, but for many average gun owners, a good compromise would be a 9mm carrying at least 9 rounds of +P hollow-points.

Don't overlook another devastating option: an all steel snub-nosed or 4 inch revolver loaded with .357 Magnum.  That will definitely make someone change their career plans!

Practice the Fundamentals, the Right Ones

Marksmanship, like any other skill, requires practice, but especially the right kind of practice.  You can throw a football with two hands, but the result won't be great.  One-handed is the preferred way, but depending on the skill, best practices are not always intuitive.

In pistol shooting, there is a standard set of fundamentals: stance, grip, aiming, breath control, trigger control, and follow-through.  Many shooters are self-taught, so they may not be aware of all of these, or may think some of them are not important.  In fact, many shooters will achieve a reasonable skill level without paying attention to some of these, like stance or follow-through, which seems to reinforce the idea that they are just concept names.  The fact is, they are all important, but with varying weights.

If you have a mutual fund, your money is invested in different stocks, but with exposure based on risk. More money is invested in stocks with low risk, and less in those with higher risk.  They are all important, but have different roles in your portfolio.

And so it is with shooting.  All the fundamentals are important, but some are of maximum importance.  As a pistol instructor, I often see students fall short in their goals/expectations, and nearly always for one (or both) of two reasons:  aiming, and trigger control.

• Aiming.  I have caught students looking over the barrel of the gun, and not through the sights. No good.  Sometimes the front and rear sights are not aligned properly (horizontally and vertically).  Also no good, although sometimes that will seem to work at a very close distance.  The biggest issue, probably, is focusing the vision (the focal point) on the target instead of the front sight.  That is not intuitive to most new shooters, and again, will often work at a close distance.  I have seen shooters hit center mass at 3 yards, yet be unable to hit anywhere on the paper at 7 yards, just because of that.
• Trigger Control.  This is probably the most common problem I see: jerking the trigger.  Most newer shooters don't understand how critical it is for the muzzle to not move at all as the trigger is moved to the rear.  For safety reasons, most guns don't have a hair trigger; a certain amount of force is required to overcome the trigger spring, and to disengage the sear so the gun will fire.  If you are too ham-fisted with that, the muzzle will be pulled off target, and even a hair's-width will make a big difference.  I tell students to take up the slack (take-up) in the trigger, and squeeeeeze slowly (1.5 sec) until the gun fires, and don't anticipate or react to recoil.  Torque on the trigger must be evenly balanced, left and right.  With experience, that 1.5 sec can come down to 1 sec or less, but it will never be 1/10 sec.  Get over it; this is not the movies.

Make those two fundamentals the centerpiece of your practice regimen, then polish with the other four, and you will see good results.

FBI 9MM Justification, FBI Training Division

May 6, 2014

FBI Training Division: FBI Academy, Quantico, VA
Executive Summary of Justification for Law Enforcement Partners

Caliber debates have existed in law enforcement for decades

Most of what is “common knowledge” with ammunition and its effects on the human target are rooted in myth and folklore

Projectiles are what ultimately wound our adversaries and the projectile needs to be the basis for the discussion on what “caliber” is best

In all the major law enforcement calibers there exist projectiles which have a high likelihood of failing LEO’s in a shooting incident and there are projectiles which have a high ting incident likelihood of succeeding for LEO’s in a shooting incident

Handgun stopping power is simply a myth

The single most important factor in effectively wounding a human target is to have penetration to a scientifically valid depth (FBI uses 12” – 18”)

LEO’s miss between 70 – 80 percent of the shots fired during a shooting incident

Contemporary projectiles (since 2007) have dramatically increased the terminal effectiveness of many premium line law enforcement projectiles (emphasis on the 9mm Luger offerings)

9mm Luger now offers select projectiles which are, under identical testing conditions, I outperforming most of the premium line .40 S&W and .45 Auto projectiles tested by the FBI

9mm Luger offers higher magazine capacities, less recoil, lower cost (both in ammunition and wear on the weapons) and higher functional reliability rates (in FBI weapons)

The majority of FBI shooters are both FASTER in shot strings fired and more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W (similar sized weapons)

There is little to no noticeable difference in the wound tracks between premium line law Auto enforcement projectiles from 9mm Luger through the .45 Auto

Given contemporary bullet construction, LEO’s can field (with proper bullet selection) 9mm Lugers with all of the terminal performance potential of any other law enforcement pistol caliber with none of the disadvantages present with the “larger” calibers

 

Justification for Law Enforcement Partners
Rarely in law enforcement does a topic stir a more passionate debate than the choice of handgun caliber made by a law enforcement organization. Many voice their opinions by repeating the old adage “bigger is better” while others have “heard of this one time” where a smaller caliber failed and a larger caliber “would have performed much better.” Some even subscribe to the belief that a caliber exists which will provide a “one shot stop.” It has been stated, “Decisions on ammunition selection are particularly difficult because many of the pertinent issues related to handguns and ammunition are firmly rooted in myth and folklore.” This still holds as true today as it did when originally stated 20 years ago.

Caliber, when considered alone, brings about a unique set of factors to consider such as magazine capacity for a given weapon size, ammunition availability, felt recoil, weight and cost. What is rarely discussed, but most relevant to the caliber debate is what projectile is being considered for use and its terminal performance potential.

One should never debate on a gun make or caliber alone. The projectile is what wounds and ultimately this is where the debate/discussion should focus. In each of the three most common law enforcement handgun calibers (9mm Luger, .40 Smith & Wesson and .45 AUTO) there are projectiles which have a high likelihood of failing law enforcement officers and in each of these three calibers there are projectiles which have a high likelihood of succeeding for law enforcement officers during a shooting incident. The choice of a service projectile must undergo intense scrutiny and scientific evaluation in order to select the best available option.

Understanding Handgun Caliber Terminal Ballistic Realities
Many so-called “studies” have been performed and many analyses of statistical data have been undertaken regarding this issue. Studies simply involving shooting deaths are irrelevant since the goal of law enforcement is to stop a threat during a deadly force encounter as quickly as possible. Whether or not death occurs is of no consequence as long as the threat of death or serious injury to law enforcement personnel and innocent third parties is eliminated.

“The concept of immediate incapacitation is the only goal of any law enforcement shooting and is the underlying rationale for decisions regarding weapons, ammunition, calibers and training.”1

Studies of “stopping power” are irrelevant because no one has ever been able to define how much power, force, or kinetic energy, in and of itself, is required to effectively stop a violent and determined adversary quickly, and even the largest of handgun calibers are not capable of delivering such force. Handgun stopping power is simply a myth. Studies of so-called “one shot stops” being used as a tool to define the effectiveness of one handgun cartridge, as opposed to another, are irrelevant due to the inability to account for psychological influences and due to the lack of reporting specific shot placement. In short, extensive studies have been done over the years to “prove” a certain cartridge is better than another by using grossly flawed methodology and or bias as a precursor to manipulating statistics. In order to have a meaningful understanding of handgun terminal ballistics, one must only deal with facts that are not in dispute within the medical community, i.e. medical realities, and those which are also generally accepted within law enforcement, i.e. tactical realities.

1 Handgun Wounding Factors and Effectiveness: Firearms Training Unit, Ballistic Research Facility, 1989.
 
Medical Realities
Shots to the Central Nervous System (CNS) at the level of the cervical spine (neck) or above, are the only means to reliably cause immediate incapacitation. In this case, any of the calibers commonly used in law enforcement, regardless of expansion, would suffice for obvious reasons. Other than shots to the CNS, the most reliable means for affecting rapid incapacitation is by placing shots to large vital organs thus causing rapid blood loss. Simply stated, shot placement is the most critical component to achieving either method of incapacitation.

Wounding factors between rifle and handgun projectiles differ greatly due to the dramatic differences in velocity, which will be discussed in more detail herein. The wounding factors, in order of importance, are as follows:

A. Penetration:
A projectile must penetrate deeply enough into the body to reach the large vital organs, namely heart, lungs, aorta, vena cava and to a lesser extent liver and spleen, in order to cause rapid blood loss. It has long been established by expert medical professionals, experienced in evaluating gunshot wounds, that this equates to a range of penetration of 12-18 inches, depending on the size of the individual and the angle of the bullet path (e.g., through arm, shoulder, etc.). With modern properly designed, expanding handgun bullets, this objective is realized, albeit more consistently with some law enforcement projectiles than others.


B. Permanent Cavity:
The extent to which a projectile expands determines the diameter of the permanent cavity which, simply put, is that tissue which is in direct contact with the projectile and is therefore destroyed. Coupled with the distance of the path of the projectile (penetration), the total permanent cavity is realized. Due to the elastic nature of most human tissue and the low velocity of handgun projectiles relative to rifle projectiles, it has long been established by medical professionals, experienced in evaluating gunshot wounds, that the damage along a wound path visible at autopsy or during surgery cannot be distinguished between the common handgun calibers used in law enforcement. That is to say an operating room surgeon or Medical Examiner cannot distinguish the difference between wounds caused by .35 to .45 caliber projectiles.

C. Temporary Cavity:
The temporary cavity is caused by tissue being stretched away from the permanent cavity. If the temporary cavity is produced rapidly enough in elastic tissues, the tensile strength of the tissue can be exceeded resulting in tearing of the tissue. This effect is seen with very high velocity projectiles such as in rifle calibers, but is not seen with handgun calibers. For the temporary cavity of most handgun projectiles to have an effect on wounding, the velocity of the projectile needs to exceed roughly 2,000 fps. At the lower velocities of handgun rounds, the temporary cavity is not produced with sufficient velocity to have any wounding effect; therefore any difference in temporary cavity noted between handgun calibers is irrelevant. “In order to cause significant injuries to a structure, a pistol bullet must strike that structure directly.”2

2 DiMaio, V.J.M.: Gunshot Wounds, Elsevier Science Publishing Company, New York, NY, 1987, page 42.

D. Fragmentation:
Fragmentation can be defined as “projectile pieces or secondary fragments of bone which are impelled outward from the permanent cavity and may sever muscle tissues, blood vessels, etc., apart from the permanent cavity”3. Fragmentation does not reliably occur in soft tissue handgun wounds due to the low velocities of handgun bullets. When fragmentation does occur, fragments are usually found within one centimeter (.39) of the permanent cavity.4 Due to the fact that most modern premium law enforcement ammunition now commonly uses bonded projectiles (copper jacket bonded to lead core), the likelihood of fragmentation is very low. For these reasons, wounding effects secondary to any handgun caliber bullet fragmentation are considered inconsequential.

3 Fackler, M.L., Malinowski, J.A.: “The Wound Profile: A Visual Method for Quantifying Gunshot Wound Components”, Journal of Trauma 25: 522-529, 1958. 

4 Handgun Wounding Factors and Effectiveness: Firearms Training Unit, Ballistic Research Facility, 1989.

Psychology
Any discussion of stopping armed adversaries with a handgun has to include the psychological state of the adversary. Psychological factors are probably the most important relative to achieving rapid incapacitation from a gunshot wound to the torso.5 First and foremost, the psychological effects of being shot can never be counted on to stop an individual from continuing conscious voluntary action. Those who do stop commonly do so because they decide to, not because they have to. The effects of pain are often delayed due to survival patterns secondary to “fight or flight” reactions within the body, drug/alcohol influences and in the case of extreme anger or aggression, pain can simply be ignored. Those subjects who decide to stop immediately after being shot in the torso do so commonly because they know they have been shot and are afraid of injury or death, regardless of caliber, velocity, or bullet design. It should also be noted that psychological factors can be a leading cause of incapacitation failures and as such, proper shot placement, adequate penetration, and multiple shots on target cannot be over emphasized.

5 Ibid.

Tactical Realities
Shot placement is paramount and law enforcement officers on average strike an adversary with only 20 – 30 percent of the shots fired during a shooting incident. Given the reality that shot placement is paramount (and difficult to achieve given the myriad of variables present in a deadly force encounter) in obtaining effective incapacitation, the caliber used must maximize the likelihood of hitting vital organs. Typical law enforcement shootings result in only one or two solid torso hits on the adversary. This requires that any projectile which strikes the torso has as high a probability as possible of penetrating deeply enough to disrupt a vital organ.

The Ballistic Research Facility has conducted a test which compares similar sized Glock pistols in both .40 S&W and 9mm calibers, to determine if more accurate and faster hits are achievable with one versus the other. To date, the majority of the study participants have shot more quickly and more accurately with 9mm caliber Glock pistols. The 9mm provides struggling shooters the best chance of success while improving the speed and accuracy of the most skilled shooters.

CONCLUSION
While some law enforcement agencies have transitioned to larger calibers from the 9mm Luger in recent years, they do so at the expense of reduced magazine capacity, more felt recoil, and given adequate projectile selection, no discernible increase in terminal performance.

Other law enforcement organizations seem to be making the move back to 9mm Luger taking advantage of the new technologies which are being applied to 9mm Luger projectiles. These organizations are providing their armed personnel the best chance of surviving a deadly force encounter since they can expect faster and more accurate shot strings, higher magazine capacities (similar sized weapons) and all of the terminal performance which can be expected from any law enforcement caliber projectile.

Given the above realities and the fact that numerous ammunition manufacturers now make 9mm Luger service ammunition with outstanding premium line law enforcement projectiles, the move to 9mm Luger can now be viewed as a decided advantage for our armed law enforcement personnel.

NOTE: recent ballistics studies have shown that 9mm +P has greater transfer of energy than a standard .40 cal bullet.

The Self-Defense Mindset

The author Robert Heinlein famously said, "An armed society is a polite society". If you think that is not true, just go to a gun show. Those folks are NOT armed in that building, yet most of them carry a gun every day, everywhere else. The Constitution has given us the right to be armed for self defense, and the State of Texas has wisely extended that right for trained and vetted citizens to be licensed to carry a concealed weapon.

Do you have a license to carry (CHL)?  More to the point, if you do, do you actually carry a gun every day, or just when going somewhere dangerous? (NOTE: going someplace dangerous is asking for trouble, anyway.) Besides, criminals might expect a citizen to be carrying a gun in a dangerous place; they will cause trouble in "safe" places.

A number of recent events have driven home the wisdom of the saying, "carry every day or guess right".

June 21. Two men leaving a Japanese restaurant in North Dallas are acosted by two armed robbers. One of the victims produces a gun and kills one robber; the other flees.

June 21. Three men stage a "push-in" robbery of an apartment in Dallas. After a gunfight, one robber is wounded and arrested; two others flee; the head of the victim family is killed. If he had not fought back, do you think the outcome would have been better? Read on.

June 10. An armed robber robs a convenience store in The Colony, a suburb of Dallas. The owner, alone in the store, gives him the money and offers no resistance. He kills her just for fun.

June 17. A white visitor to a Bible study class at a black church in Charleston, SC, opens fire, killing 9 people.

Sep 26, 2014. A female employee of a small food processing plant in Moore, OK, a suburb of Oklahoma City, is beheaded by a recently fired worker. He is shot by another employee.

None of these locations would be judged "dangerous", yet all of theme were. Could all of these had better outcomes with more armed citizens on the scene? Not necessarily. Not everyone is physically or emotionally capable of carrying or discharging a firearm, but many are.

The most tragic of these events, because it was so avoidable, is the church shooting in Charleston. Avoidable, because churches in SC, by state law, are "gun-free zones". There is a provision for churches to opt out of that, but as of this date, there has been no information to suggest that the church did that. Our experience in Texas has been that businesses that must take an affirmative action to allow guns seldom do. The number of people in that Bible study was small enough that there still might not have been a gun there, anyway, but if there had been, we would be talking about one or two dead instead of nine.

John Lott, the economist and data-geek, has demonstrated that since 1950, the overwhelming majority of mass shootings have occurred in gun-free zones.  James Holmes, the theater shooter in Colorado, avoided one theater because it was not a gun-free zone, and chose another one further away because it was.

When will we ever get this right?  And when will you start carrying daily?

Cop-killer Bullets?

Hollow-point (expanding) bullets have been around for years, yet many people still think of these as a bad thing, intended to kill cops or penetrate body armor. Much of this misinformation is fostered by the media, which collectively hates guns and gun owners, and typically can't even get the terminology right (how often do you hear them refer to clips instead of magazines?).

First, let's understand a concept in basic ballistics.  Force = Mass X Energy
Smaller bullets generate less force, and slower bullets generate less force. There is a bell curve here, so a smaller, faster bullet could have greater penetration than a larger, slower one.  Larger bullets are also heavier, requiring more powder to achieve even a comparable velocity.  There is a law of diminishing returns involved, so there is a practical limit to how much velocity you can get from a larger bullet.  That is one reason many police departments prefer the .40 cal or .357 Sig chamberings over the .45.  I have a pistol that fires a .30 cal bullet (smaller than a 9mm), which has more penetration than a .357 Magnum.  Why?  Because the bullet goes very, very fast.  It will penetrate body armor, as will almost all rifle cartridges.  Speed kills.

The problem, from a defensive standpoint, is that many larger caliber handguns will over-penetrate a human body, come out the other side, and potentially injure or kill some innocent person.  After all, the hole it makes is only slightly larger than a pencil, and unless the bullet strikes bone, it goes right through.  This became both a public safety and a liability issue for police, as well as efficacy: it might not hurt an enraged criminal enough to slow him down.

Thus, the hollow-point design was born.  It expands in flight, and expands more on contact, to create a piece of schrapnel as much as double the size of the original bullet.  Over-penetration is virtually impossible, and the increased surface damage and resultant pain greatly magnifies the stopping power of the bullet. It has no chance of going through body armor, but that was never the point, anyway.  The point was to stop the criminal, and protect the public.

Hollow-points (HP) cost a little more than standard Full Metal Jacket (FMJ) bullets, so I always recommend people use FMJ at the range, and HPs in a defensive gun.  There is not a significant difference in the way they shoot, but people will sometimes finish a range session by shooting maybe 6 rounds of HP, to stay in touch with it.  In a defense situation, they will not notice any difference.