Full Metal Jacket vs. Jacketed Hollow Point

Full Metal Jacket vs. Jacketed Hollow Point
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Full Metal Jacket vs. Jacketed Hollow Point

After much consideration, you've decided to buy a gun for self-defense, hunting, or sport. Congratulations, and welcome to the club. Now you need to figure out what kind of ammo to buy.

It's not as simple as just getting the right caliber, as multiple types of ammunition can fit into a single gun model. In addition, these ammo types all have different constructions, uses, and results.

Two of the most common styles are Full Metal Jacket (FMJ) and Jacketed Hollow Point (JHP) ammunition. Understanding these two kinds of bullets and knowing your gun helps you choose the best ammo to suit your needs.


How Bullets are Made

When manufacturing ammunition, most bullets follow a similar construction process. A lead core at the center of a round adds weight to the bullet and is created with lead or lead alloy that is melted down and then poured into a mold to create a solid core.

However, the lead alone is too soft and easily deformed, limiting the shot's accuracy. The core is then coated with a harder metal through electroplating or swaging.

The next step in the production process is the creation of the jacket - typically using copper because it is more substantial yet malleable enough to grip the rifling in a gun's barrel during firing.

The jacket helps prevent the lead from being exposed and deforming upon impact with the target while providing increased penetration and improved accuracy.

While the specific manufacturing process can vary depending on the particular type and use of the bullet, the foundational process will generally remain the same.

Additional production steps involved are as follows:

Melting the lead: Lead is melted down in industrial-sized furnaces or pots, removing any objectionable impurities through a process called fluxing.

Pouring the lead: The melted lead is then poured into steel molds that contain multiple cavities (so that multiple rounds can be made simultaneously) to create the solid core of the bullet.

Coating the bullet: The bullet core is then coated with a harder metal, typically copper, through electroplating or swaging.

Electroplating is a process by which metal ions migrate via a solution from a positive electrode to a negative one. An electrical current passing through the solution causes objects at the cathode to be coated by the metal in the solution.

Swaging is a compressive cold-forming process used to manipulate the shape of metal. Throughout the process, a metal workpiece is forced through a die, and as it's pushed through, it takes the die's shape.

Cutting the bullet: The bullet will be cut to the desired shape and length by trimming away any excess material. The round may also be engraved with identifying markings, such as the caliber or manufacturer's logo.

Quality control: The finished bullets are inspected for defects and imperfections, then weighed to ensure consistency in size and weight.


Ammunition Components

Full Metal Jacket

Full Metal Jacket, or FMJ ammunition, is a common bullet variation that gets its name from the jacket that covers the entire bullet.

FMJ is mainly characterized by a lead core that is completely encased in a harder metal (typically copper) to prevent the lead from being exposed and deforming upon impact with a target.

FMJ's copper jacket also provides increased accuracy and penetration by maintaining the bullet's shape as it travels through the air before impacting a target.

Commonly used for target shooting and military training, FMJ ammunition typically has less recoil than other ammo types and tends to be more affordable.

Full Metal Jacket ammunition is also used by law enforcement and military personnel for situations where over-penetration is a concern, as the FMJ bullet is less likely to fragment or expand upon impact with a target, reducing the risk of unintended casualties or property damage.

However, FMJ ammunition is considered less effective than other variations of ammo, such as hollow point bullets, for self-defense purposes. This is primarily due to the bullet leaving smaller entry/exit wounds and being unable to quickly stop a target.

Full Metal Jacket Ammo Types

Features of FMJ Ammunition

Increased Penetration: FMJ ammunition typically has greater penetration than other types of ammunition because the bullet retains its shape and does not expand upon impact with a target. This makes Full Metal Jackets a good choice for target shooting, military training, and situations where over-penetration is not a concern.

Reduced Barrel Fouling: FMJ ammo produces less fouling in the barrel of the firearm than other types of ammunition, which means that the firearm requires less cleaning and maintenance.

Reliable Feeding: FMJ ammunition is less likely to jam or fail to feed in a firearm than other types of ammunition because the bullet has a consistent shape and size.

Cost-Effective: FMJ ammunition is generally less expensive than other types of ammunition, which makes it a good choice for target shooting, military training, and other high-volume shooting activities.

Consistent Accuracy: Full Metal Jacket ammunition tends to be more consistently accurate than other types of ammunition because of its uniform shape and weight, which helps to reduce variations in trajectory.

Legal For Hunting: FMJ ammo is an excellent choice for hunters looking for affordable and reliable ammunition. *Always check state and local hunting requirements (IE) Ammunition guidelines.


Benefits of FMJ Ammunition

Penetration
FMJ bullets are designed to penetrate targets effectively. The bullet's lead core is enclosed by a harder metal, such as copper or steel, which helps maintain its shape during impact.

This design allows for deep penetration into the target, making it ideal for situations where penetration is necessary, such as military and law enforcement applications.

Reliable Feeding
FMJ rounds have a smooth, rounded shape that facilitates reliable feeding in semi-automatic firearms. The bullet's shape reduces the likelihood of jams or feeding issues, ensuring consistent and reliable cycling of the firearm.

Over-Penetration Control

While penetration is an advantage in certain situations, FMJ bullets tend to have less risk of over-penetration compared to some other bullet types.

This can be important in scenarios where collateral damage must be minimized or when shooting in crowded environments.

Range Practice
Full metal jacket rounds are commonly used for range practice and training purposes. They provide a similar shooting experience to other bullet types while being more economical.

FMJ ammunition allows shooters to practice their marksmanship skills and become familiar with their firearms without the expense of specialized ammunition.

Reliability
FMJ rounds are known for their reliability and consistency. The design of the bullet, with its full metal jacket and solid construction, enhances its overall reliability and ensures predictable performance shot after shot.

Cost-Effective
FMJ ammunition is often more cost-effective than other bullets, such as hollow points or specialty rounds. This affordability makes it popular for target shooting, training, and plinking.


Jacketed Hollow Point

Jacketed Hollow Point, or JHP ammunition, is a specialized type of bullet primarily designed for law enforcement or self-defense due to its balance of stopping power and reduced risk of over-penetration.

Similar in construction to FMJ ammo, JHP is made with a hole in the tip of the bullet, giving it a hollowed center enabling the round to make contact with the target, then expand like an umbrella creating a cavity. 

When the cavity on Jacketed Hollow Point ammunition expands upon impact, it slows the round down, increasing the size of the wound channel, making it much more effective at stopping the target quickly.

The JHP's jacket also helps control the bullet's expansion by preventing it from fragmenting, reducing the risk of over-penetration and collateral damage.

Although Jacketed Hollow Points are generally more expensive than FMJ ammunition, they can also be less reliable in some firearm models due to their shape and design.

Additionally, JHP ammo is also not legal for hunting use in some areas, as they are considered too destructive and can cause unnecessary suffering to the animal being hunted.

Jacketed Hollow Point Ammo Types

Features of JHP Ammunition

Reduced Risk of Collateral Damage: Because JHP ammunition is designed to expand and stay within the target, it reduces the risk of collateral damage and injury to bystanders or unintended targets.

Improved Wound Channel: JHP ammunition creates a larger and more devastating wound channel than FMJ ammunition, which increases the likelihood of incapacitating the target quickly and effectively.

Greater Accuracy: JHP ammunition typically has greater accuracy than FMJ ammunition because the bullet's expansion upon impact reduces the risk of ricochet and helps the bullet stay on course.

Legal for Self-Defense: JHP ammunition is legal for self-defense in most areas, which makes it a good choice for those who are looking for a reliable and effective ammunition option for personal protection.

Effectiveness: JHP ammunition is effective against a wide range of targets, including soft tissue, bone, and other materials, which makes it a versatile choice for hunting, self-defense, and law enforcement applications.


Benefits of JHP Ammunition

Expansion
The primary advantage of JHP ammunition is its ability to expand upon impact. The bullet is designed with a hollowed-out tip covered by a jacket.

When the bullet strikes a target, the hollow point is designed to deform, causing the bullet to expand. This expansion creates a larger wound channel, increasing the stopping power and effectiveness of the round.

Energy Transfer
The expansion of a JHP bullet allows for effective energy transfer to the target. As the bullet expands, it transfers a significant amount of kinetic energy to the surrounding tissue, maximizing stopping power and increasing the likelihood of incapacitating the threat.

Controlled Penetration
Jacketed hollow point rounds are engineered to provide controlled penetration. While they expand upon impact, they are designed to limit excessive penetration beyond the target.

This characteristic helps reduce the risk of over-penetration, which can pose a danger to innocent bystanders or objects behind the intended target.

Stopping Power
The combination of expansion and energy transfer of JHP ammunition contributes to its enhanced stopping power.

The larger wound channel created by the expanded bullet increases the likelihood of incapacitating an attacker quickly, potentially preventing further harm.

Reduced risk of over-penetration
JHP ammunition is often preferred in self-defense scenarios due to its reduced risk of over-penetration. Unlike full metal jacket bullets that can pass through a target and continue traveling, JHP bullets are designed to expand and slow down upon impact, reducing the likelihood of hitting unintended targets.

Terminal ballistics
Jacketed hollow point ammunition is engineered to optimize terminal ballistics, which refers to the bullet's performance upon impact with the target.

The expansion and controlled penetration of JHP rounds are specifically designed to maximize the effectiveness of the bullet and improve its terminal performance.

Before and After Fired JHP Ammo

How to Choose Between FMJ and JHP Ammo

There is no one right ammunition type for every shooter, and the choice between FMJ and JHP ammunition ultimately depends on your specific needs and intended use. However, here are some common factors to consider when making your choice:

Purpose: What is the intended use of the ammunition? Are you using the ammunition for target shooting, practice, or self-defense?

Penetration: Consider the level of penetration needed for your specific application. FMJ ammunition typically has greater penetration than JHP ammunition because the bullet does not expand upon impact.

Cost: FMJ ammo is generally less expensive than JHP ammunition, which makes it a good choice for target shooting and other high-volume shooting activities.

The important thing to remember when choosing between Full Metal Jacket and Jacketed Hollow Point is to find the ammo that works best for your gun and your needs.

Finally, gun owners should always check their state's laws to ensure there aren't restrictions on bullet types. Once you have that cleared, practice with FMJ and JHP ammo to get a feel for both.

Disclaimer: Always check with your state and local laws for restrictions before ordering ammunition, and make sure you use the correct ammunition for your specific firearm.

Comments
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H. Lynn Norton
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For most calibers JHP IS best. For .32 cal. and below, hollow points, with a few exceptions(7.62X28 for example), do not provide enough penetration to reliably take down a target in a self-defence situation. I carry my .32 loaded with FMJ. My .380 to my 1911 are loaded with JHP when I carry them.
William Hollis
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Thanks for your information.
David Zimprich
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Thanks for your information.
Gonzalez Mario J
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Excelent info !!!
Ranger Rick
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I carry both. Hard target comes up I go to FMJ mag. Otherwise, I go with H.P.
Thomas
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Different confrontations call for different solutions Fmj ,hollow points and cutting edge bullets all give the best results under different circumstances is opponent under light cover wearing bullet proof clothes moving in and out of cover ,a mixture is the best choice. Probably out of a Glock 17l ,or HK mk 23. With good barrels both give 1” or better at 25 yds.
Pete
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Not much of an article. I guess it's intended for someone who knows nothing literally about bullets.
Wayne
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Great info for new shooters.
Kim.
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I use HP in my 380s. But I havent really understood my bullets. So for me this was really informative. Thank you!
RM Parkerson
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Several direct contradictions in the article concerning both accuracy and collateral damage between the FMJ and the JHP: Examples (copied directly from the above article): FMJ's copper jacket also provides increased accuracy and penetration by maintaining the bullet's shape as it travels through the air before impacting a target. Greater Accuracy: JHP ammunition typically has greater accuracy than FMJ ammunition because the bullet's expansion upon impact reduces the risk of ricochet and helps the bullet stay on course. Full Metal Jacket ammunition is also used by law enforcement and military personnel for situations where over-penetration is a concern This makes Full Metal Jackets a good choice for target shooting, military training, and situations where over-penetration is not a concern.