Walk into almost any gun range in Palm Beach or Broward County and ask the person next to you what they carry in their defensive handgun. A surprising number will say FMJ, full metal jacket, because it is cheaper, because it is what they train with, or because they have never thought hard about the difference.

This is one of those topics where the answer from a defensive shooting perspective is clear, not a matter of ongoing debate. Hollow point ammunition is the correct choice for a defensive carry load. FMJ has its place, but that place is the range, not the holster.

Here is why that answer is not even close, and what it means practically for anyone carrying a firearm in South Florida.

The Physical Difference Between FMJ and Hollow Point

Before getting into why one is better for defense, it helps to understand what each round actually does when it hits a target.

Full Metal Jacket (FMJ)

A full metal jacket round has a lead core fully encased in a harder metal shell, typically copper or a copper alloy. The nose is rounded or pointed and solid. On impact with soft tissue, an FMJ round does not change shape. It passes through in a relatively straight line, creating a wound channel roughly equal to its original diameter and often exiting the far side of the target entirely.

That behavior makes FMJ ideal for range training. It is inexpensive to manufacture, feeds reliably across virtually all semi-automatic platforms, and produces consistent recoil for repetition-based skill development. It is not, however, designed to stop a threat efficiently.

Hollow Point (HP)

A hollow point round has an open cavity in the tip of the bullet. When that cavity contacts soft tissue and hydraulic pressure builds inside it on impact, the bullet mushrooms outward, expanding its diameter significantly. A 9mm hollow point that started at .355 inches may expand to .60 to .70 inches or more. That expanded diameter creates a larger wound channel, transfers more energy to the target, and, critically, slows the bullet enough that it is far less likely to exit the far side of the threat and continue into whatever is behind it.

That combination of expansion, energy transfer, and reduced over-penetration is exactly what a defensive round needs to do. It concentrates the round's effect on the threat rather than distributing it through the threat and into the surrounding environment.

Why Over-Penetration Is a Serious Problem With FMJ

The over-penetration issue with FMJ is not theoretical. It is one of the primary reasons law enforcement agencies moved to hollow point ammunition decades ago. An FMJ round that passes completely through a threat does not stop at the threat. It continues downrange into whatever or whoever is behind them.

In the South Florida context, defensive situations often occur in dense environments: apartment buildings, retail stores, parking lots, restaurant dining rooms. A round that exits a threat in any of those environments has a meaningful probability of hitting an unintended person. The carrier of that firearm bears responsibility for every round fired, including where it ends up after passing through the intended target.

Hollow point ammunition, by expanding and slowing within the target, significantly reduces that risk. It is not a guarantee against over-penetration in every scenario, but it is the engineering solution designed specifically to address that problem.

The Legal Dimension Carriers Need to Understand

This is where the FMJ vs hollow point conversation gains a layer that goes beyond ballistic performance. In a post-shooting legal proceeding in Florida, the ammunition a carrier chose to load is part of the record. Prosecutors, opposing counsel, and expert witnesses will examine it.

Carrying FMJ in a defensive context can be used as evidence against a shooter because hollow point ammunition is the industry and law enforcement standard specifically because it reduces collateral damage. A prosecutor can credibly argue that a carrier who chose FMJ over hollow point accepted a higher risk of injuring bystanders.

Conversely, a carrier who loaded quality defensive hollow point ammunition made the same choice as every major law enforcement agency in the country. That context is documented and defensible. The ammunition choice itself communicates responsible intent.

Does Hollow Point Compromise Reliability?

This is a legitimate concern and one worth addressing directly. Early hollow point designs sometimes had feed reliability issues in semi-automatic pistols, particularly those with tighter tolerances. The open cavity nose profile fed differently than the rounded FMJ profile some older pistol designs were optimized for.

Modern defensive hollow point ammunition from established manufacturers is engineered to feed reliably in all quality semi-automatic pistols. The concern about hollow point reliability is largely a legacy of older ammunition technology and older pistol designs. In a current production Glock, SIG Sauer, Smith and Wesson M&P, or Springfield Armory handgun loaded with Federal HST, Speer Gold Dot, or Hornady Critical Defense, feed reliability is not a meaningful concern.

Recommended Defensive Hollow Point Loads

Not all hollow point ammunition performs equally. The following loads consistently appear at the top of independent ballistic gelatin testing and are trusted by law enforcement agencies and defensive shooting instructors across the country. All three meet the FBI's minimum penetration standard of 12 inches in bare gelatin and through clothing barriers.

How to Think About FMJ vs Hollow Point in a Training Context

The practical approach most defensive shooting instructors recommend is straightforward: train with FMJ to keep practice costs manageable, carry hollow point for actual defensive use, and periodically shoot a box of carry ammunition to verify function and confirm point of impact.

Addressing the Cost Concern

The most common reason carriers give for loading FMJ in their defensive pistol is cost. Hollow point defensive ammunition costs more per round than FMJ practice ammo, sometimes significantly more. That cost difference is real and worth acknowledging.

The carry load, however, is not the training load. A carrier who loads 15 rounds of defensive hollow point in a Glock 19 is not burning through boxes of premium ammunition at the range. Those 15 rounds sit in the magazine until either the gun is cleaned and the magazine is rotated, or a defensive situation requires them. The cost of 15 to 20 rounds of quality defensive ammunition, replaced every six months to a year as part of regular maintenance, is a negligible expense relative to the cost of the firearm, the holster, and any training courses.

Saving a few dollars on ammunition by carrying FMJ is a false economy when weighed against the defensive performance difference and the legal exposure that comes with choosing a load not designed for defensive use.

Frequently Asked Questions

Can hollow point ammunition fail to expand?

Yes, under certain conditions. Heavy clothing can sometimes pack the hollow point cavity before the round reaches tissue, reducing or preventing expansion. This is why premium defensive loads like Hornady Critical Defense use a polymer tip that prevents cavity clogging, and why the FBI tests ammunition through multiple clothing barriers rather than bare gelatin alone. Even a hollow point that fails to expand performs at least as well as FMJ. A hollow point that expands performs significantly better. The risk of expansion failure is not a reason to choose FMJ.

Is there a reason police switched from FMJ to hollow point?

Law enforcement agencies moved to hollow point ammunition primarily because of documented over-penetration incidents with FMJ loads. Rounds passing through suspects and injuring bystanders or other officers were the driving force behind the transition. The FBI's adoption of hollow point as the standard for agent-issued ammunition formalized what departments across the country were already concluding from their own incident reports. The transition happened decades ago and has not reversed.

Does hollow point ammo work the same in shorter barrels?

Barrel length affects velocity, and velocity affects expansion. A hollow point designed for a full-size pistol with a 4-inch barrel may not achieve sufficient velocity to expand reliably from a compact pistol with a 3-inch barrel. This is a real consideration for South Florida carriers using micro-compact pistols. Hornady Critical Defense and Federal HST are consistently recommended for shorter barrels because they are engineered to expand across a wider velocity range. Checking the manufacturer's velocity data against the actual barrel length of the carry gun is due diligence worth doing.

Should a home defense gun be loaded the same as a carry gun?

Yes. The same defensive rationale applies to a home defense firearm staged in a safe or on a nightstand. In a residential environment, over-penetration through walls is a serious concern, particularly in South Florida where homes tend to be single-story with common walls close to neighbors or family members. Hollow point ammunition reduces that risk meaningfully. A home defense pistol loaded with FMJ creates the same over-penetration liability in a residential context that it creates in a crowded public space.

The Bottom Line

The FMJ vs hollow point question for defensive carry has a clear answer: hollow point. The expansion, energy transfer, and reduced over-penetration of a quality defensive hollow point load are the engineering solution specifically designed for the defensive use case. FMJ passes through, continues into whatever is behind the threat, and does not transfer its energy where it is needed.

Every major law enforcement agency in the country made this decision decades ago. The defensive shooting instruction community is unanimous on it. The ballistic evidence supports it. And from a legal standpoint, loading quality defensive hollow point ammunition is the choice that reflects responsible intent and aligns with the professional standard.

Train with FMJ. Carry hollow point. Rotate the carry load periodically and test it in the actual carry gun. That is the complete picture for a responsible concealed carrier in South Florida.

Ammunition selection is one piece of a complete carry picture. For anyone looking to build the full foundation that responsible carry requires, Suburban Protector's concealed carry class covers ammunition, Florida law, safe handling, and defensive fundamentals in a single course designed for new and returning carriers across Palm Beach and Broward counties.