Introduction
Ever found yourself in the midst of a heated debate over the age-old question of Full Metal Jacket (FMJ) vs Hollow Point ammunition? Well, you’re about to!
As an experienced gun owner and enthusiast, I’m going to give you a complete rundown of all the differences between these two types of ammo.
Whether you’re new to the gun world or a seasoned shooter, this deep dive will give you all the information you need to understand the critical differences between full metal jacket ammo and hollow point ammo.
Spoiler alert: ammo isn’t a ballcap, so there’s no one-size-fits-all solution, but your preferences and intended use will likely be the deciding factor.
Overview of FMJ
Full Metal Jacket Details
Full metal jacket (FMJ) ammo features a bullet that is encased in a harder metal, typically copper, though other metals are used as well. The primary benefit of this design is that it helps the projectile maintain its shape and lowers the risk of fragmentation, or breaking apart, on impact. These qualities make FMJ ammo a popular choice for target shooting and military applications.
Overview of Hollow Point
Hollow Point Details
Hollow point bullets are so named because of the hollow cavity at the tip of the bullet. This cavity is generally a hemispherical void, which expands on impact.
This sudden expansion inside the soft tissue creates a much larger wound channel, transfers more energy to the target, and has an increased “tumbling” effect inside the target. This makes hollow point ammunition the favored choice for those looking for maximum stopping power on soft targets in applications such as hunting and self-defense.
Specification Chart for FMJ and Hollow Point
| Specification | FMJ | Hollow Point |
| Bullet Design | Encased in a harder metal (e.g., copper) | A hollowed-out cavity at the tip |
| Expansion | Minimal to none | Significant expansion upon impact |
| Penetration | High | Lower due to energy transfer |
| Application | Target shooting, military | Self-defense, hunting |
| Barrier penetration | More likely to over-penetrate | Less likely due to energy transfer |
Key Differences Between FMJ and Hollow Point
Expansion and Penetration
The most notable and significant difference between FMJ and hollow point rounds lies in their expansion and penetration styles.
FMJ bullets maintain their shape to a considerable degree of impact, allowing them to retain more of their energy, which is used for penetration. This makes them ideal for putting rounds through hard targets like vehicles, armor, and more.
Conversely, hollow point rounds expand significantly, making a much larger wound channel and transferring a larger portion of kinetic energy to the target. The bullet tends to “tumble” more in the wound channel, creating additional soft tissue damage and increasing stopping power.
It also has a far lower depth of penetration. Hollow-point ammo is far more effective against soft targets than FMJ ammo.
Intended Application
Another major difference between these two ammo types is their intended application. FMJ rounds are ideal for military applications not only because of their limited expansion but because they are incredibly cost-effective, which is important for military application.
Hollow-point bullets are better suited for self-defense and hunting situations. The projectile’s expansion profile delivers a far greater percentage of the kinetic energy to the target, increasing stopping power and decreasing penetration.
Barrier Penetration
The degree of barrier penetration is important to consider, particularly when looking for a self-defense or home-defense round. Hollow points are ideal for this application because they have a far lower chance of penetrating through multiple walls and potentially injuring bystanders.
FMJ rounds, on the other hand, have a high risk of over-penetration, which could result in collateral damage in self-defense situations.
This also influences which ammo you’re more likely to be allowed to use at a range. FMJ rounds are more likely to penetrate and damage the backstop or steel targets that are used in firing ranges. If you load up on FMJ and hit the range, you may be forced to buy more range-friendly hollow points when you arrive.
Cost
From a general perspective, full metal jacket ammo is much more affordable than hollow point ammo.
This is mostly due to the higher production and manufacturing costs of hollow points, and the simpler process of producing FMJ rounds. Hollow point rounds have a more complex manufacturing process, which leads to a higher price point.
For high-volume shooters, FMJ rounds are going to be much easier on the budget, but then again you’d expect that from a target ammo, not hunting ammo.
Terminal Ballistics
Terminal ballistics is the behavior of a projectile upon impacting a target. With their expansion, hollow-point rounds cause more significant soft tissue damage.
In contrast, full metal jacket rounds have limited terminal ballistics, since they largely maintain their shape and momentum, and are much more likely to pass through soft targets with little energy transfer. This means if you need to put a round through something, the FMJ is the ideal choice.
Feeding and Reliability
This is a big factor for just about every shooter, whether you’re defending yourself, or competing in a long-range shooting competition, you want your ammo to be reliable. This means feeding and ejecting smoothly, especially in semi-auto firing.
FMJ rounds are often more reliable when it comes to feeding, and they exhibit fewer FTF issues, due to their more rounded profile and smoother tip. Hollow-point ammo, with the modified expanding tip, typically has a less smooth profile.
While this issue has been addressed over the years with design and manufacturing refinements, some shooters still swear that hollow-point rounds jam more often in semi-automatic weapons.
Legal Restrictions
There are many jurisdictions where not only are there firearms restrictions, but there are restrictions on the type of ammo shooters can own as well. Making sure you’re aware of your local laws and regulations can save you some legal hassle for using prohibited rounds.
FMJ Pros & Cons
- Cost-effective
- Suitable for target shooting and competition
- A higher degree of penetration
- Limited expansion
- Risk of over-penetration
Hollow Point Pros & Cons
- Greater stopping power
- Ideal for self-defense and hunting
- Lower risk of over-penetration
- More expensive
- Less suitable for target shooting
Other Alternatives to Consider
Soft Point (SP)
Soft point ammo combines some of the traits of both FMJ and hollow point ammo. Soft point bullets have a softer lead core, and a partial copper jacket, which gives them controlled expansion and moderate penetration. They are ideal for self-defense and hunting.
Frangible
Frangible ammo is ammo that’s designed to disintegrate upon impact. Frangible bullets are created to minimize the risk of ricochet and over-penetration. They are perfect for close-quarters shooting and training scenarios.
Ballistic Tip
These rounds are created with a polymer tip that is designed to initiate rapid expansion on impact. Ballistic tip bullets offer a very high degree of accuracy, making them suitable for both hunting and long-range shooting.
FAQs
Is it OK to use FMJ for self-defense?
FMJ rounds can be used for self-defense, but they’re not the ideal choice since they don’t expand and have a significant risk of over-penetration. Hollow point ammo or soft point bullets are generally more effective and safer for those nearby.
Why doesn’t the military use hollow points?
The military doesn’t use hollow points due to international laws. Specifically, the Hague Convention of 1899 prohibits the use of expanding bullets in warfare. This makes FMJ the default choice for military operations.
What are green tip bullets?
Green tip bullets, like the 5.56x45mm NATO M855, are equipped with a high-density steel penetrator core at the tip, jacketed in copper, with the tip painted green. They are designed for greater penetration against hard targets but have diminished effectiveness against soft tissue. The tip is painted green to differentiate the round from other 5.56x45mm NATO rounds.
Conclusion
There you have it. In the FMJ vs. hollow point showdown, it’s clearly a draw, with both options being the potential winner, depending on how you plan to use them.
Remember that FMJ offers far better cost-effectiveness and superior penetration, which makes them perfect for target shooting and military use. Hollow points, on the other hand, have far greater stopping power for soft targets and a lower risk of over-penetration, which makes them perfect for hunting and self-defense.
By understanding the key differences between these two ammo types, as well as alternatives, you’ll be better equipped to make an informed decision about what type of ammo is best for you.
