A hollow-point bullet is the type of ammunition that has a hollow tip with a cavity cut into it. The bullet is manufactured like this so that when it passes through soft tissue material, the pressure created within the pit of the cavity will force the bullet to expand outwards creating a mushroom effect. Hollow-point bullets are designed to expand and cause the diameter of penetration to grow while passing through the target, limiting the depth of penetration and creating greater tissue damage along the wound path. A hollow-point bullet is also less likely to fragment unless it hits something made of a much stronger material.
Generally, hollow-point bullets have an expansion rate of 1.7 times the original diameter of the shot. This means a 9mm hollow-point bullet, which has a diameter of .355 inches, can expand up to .60 inches when it passes through a target. If a hollow-point .45 ACP shell is being used, the same rules apply as the round can go up to .75 inches when it expands. Some hollow-point bullets can expand to double the size of their original diameter as well. This is usually dependent on the target as well as the level of penetration during expansion. The more the shot begins to expand, the more it begins to slow down penetration of the target. Most hollow-point bullets will be jacketed in order to increase penetration depth and accuracy as a non-jacketed round may fragment and fail to penetrate the target deep enough.
The Federal Bureau of Investigation (FBI) ballistic laboratories have designed a rigorous and careful ammunition testing protocol to understand and compare the performance of various types of calibers and ammo. Even though no laboratory testing can predict the performance of a bullet in a real-life situation, the “FBI Protocol” is generally regarded as an excellent approach to understanding the suitability of your ammunition for self-defense or law enforcement purposes and is accepted industry-wide. Ammunition manufacturers take care to design their bullets following the rigorous standards set by the FBI Protocol and take care to balance the construction of their bullets, materials, and intended impact velocity in order to succeed in the lab testing.
To test the performance of the ammo, it is first fired up against a block of 10% ballistic gelatin, which is carefully calibrated to ensure a density match with that of living muscle tissue. Various barriers are also put in front of the block to simulate heavy clothing, windows, car doors, walls, and residential buildings. Theoretically, a hollow-point bullet would expand and penetrate the block after passing through all of these barriers. Most of the tests are performed keeping the target at a distance of 10 feet, but can be moved up to 20 yards in some cases. The hollow-point bullets are expected to penetrate at least 12 inches but can have a maximum penetration rate of 18 inches. During these tests a careful measurement of their expansion in the ballistic gelatin is also logged.
Over-penetration of the target is analyzed cautiously. This is because bullets that penetrate and passing through the target not only poses a risk to hitting bystanders, but also implies the bullet did not expand to its ideal potential, wasting energy. Because of this, bullets penetrating less than 12 inches and penetrating above 18 inches are not authorized by the regulatory agency. When it comes to expansion, hollow-point bullets will normally expand properly when they are shot into ballistic gelatin with no barriers. However, materials such as fabric, wood, or metals can clog up the cavity in the ammo and reduce the level of expansion.
Typically, hollow-point bullets are not designed to be any more lethal than full metal jacket ammo. Instead, hollow-point ammunition is designed to stop an assailant as quickly and as efficiently as possible. With this design point in mind the user can protect himself/herself in the event of an attack by having to fire fewer rounds. In many cases a single round from a pistol might not be enough to knock down an invader and stop them in their tracks as the ammo can either be too small or penetrate the assailant. Hollow-point bullets are regarded as a better choice when it comes to self-defense and protection.
Hollow-point bullets are designed to offer the best stopping potential of handguns because of the increased wound effect on the target. These bullets make bigger wounds and keep the bullet inside the target, which makes it more of an efficient use of the shot’s energy in order to stop the assailant with the least amount of effort possible. For this reason, experts strongly advise against using practice ammo in a home-defense handgun. You should also note that a premium and high-quality ammunition has the ability to be used over the span of a long period of time. Experts still believe that it is better to cycle the ammunition through your pistol at least once in a year. An easy way to do this is by going to your local shooting range to practice– when done, clean your handgun and reload it with new hollow-point bullets.
A key point to remember when choosing defensive ammunition is to make sure that it is a reliable choice and works well with your gun. You must always make sure that the ammo feeds properly in the chamber and does not get jammed. Hollow-point bullets do not work with some older gun models, so it is always important to try some test shots with hollow-point ammo before buying stock for self-defense situations. Experts also suggest that you should fire at least a couple hundred rounds flawlessly before making a choice on your defensive ammo.