Hollow Points vs. Full Metal Jacket (FMJ) Ammo

Nothing will make up for shooting skill…

If you don’t hit your target it won’t matter if you were using the Golden Gun and firing depleted uranium rounds – you still missed.  But that doesn’t mean what you shoot isn’t important.

There’s an unwritten rule of firearm ammunition: use hollow points for your carry/home defense guns and use full-metal jacket (FMJ) for practice.

This is mainly due to the fact that FMJ rounds are significantly cheaper than your average hollow point.

It’s also due to the fact that, from a “put the attacker down” point of view, FMJ rounds aren’t exactly ideal.

9mm 115 gr Federal FMJ vs 124 gr Federal Hydrashok, Top
9mm 115 gr Federal FMJ vs 124 gr Federal Hydrashok, Top

That’s not to say that FMJ rounds are useless for defense.

Far from it, in fact.

Most NATO militaries use only FMJ rounds.  This is due to an international treaty that was signed many years ago that forbids the use of expanding rounds.  That same treaty also bans the dropping of grenades from hot air balloons, mind you, so some of the stuff might be outdated in the grand scheme of things.

However, the USA never ratified that section of the treaty…and the US Army just recently adopted hollow point ammo along with the new Sig Sauer M17 pistol.

But I digress, the FMJ is still a bullet and will still punch a hole in your average bad guy.  Stories of people “shrugging off” FMJ rounds because they “just passed right through” are rare and often exaggerated.

So Why Do We Use Hollow Points Then?

Ballistics Gel Testing
Ballistics Gel Testing, Lucky Gunner

While a full metal jacket round will still drop a bad guy, a hollow point will do it just a little bit better.  That’s not to say there aren’t all kinds of misconceptions about hollow points as well.  What I want to do today is talk about both rounds and touch on the misconceptions of both.

Or if you’re ready…check out our Ammo & Reloading Definitive Guide for our favorite ammo picks for common calibers.

Full Metal Jacket

A full metal jacket round, as we talked about in our Basic Bullet Guide, is a soft lead bullet that’s been encased in a harder metal.

When passing through soft tissue and other stuff, the bullet retains the majority of its shape.  The upside of this is that, in theory, it has an easier time retaining its lethality after passing through a barrier among other things.  It also has an easier time working in almost any gun you put it in.

The main thing, however, is that it’s just far cheaper to manufacture FMJ ammo.


So why does FMJ ammo have that “less lethal than hollow point” thing associated with it?

It comes down to physics…

Because the bullet is just passing through, for lack of a better term, it retains a great deal of its energy.  This ultimately results in 2 small holes (entrance and exit wound) and also allows the bullet to possibly continue on for a long time and hit something you don’t want it to.

Don’t get me wrong, I don’t want 2 small holes punched in me and I don’t think anyone else does either.

It’s a safe bet that anyone, and I do mean anyone who says that a person could just shrug off a shot from an FMJ round (or a given caliber) would not be willing to stand downrange of said caliber and attempt to shrug it off.

That being said, what about the common alternative?

Hollow Points

Take an FMJ round, then drill a hole in the tip.  Hey look, the point of the bullet is now hollow.  I wonder what we could call it…

Ok, it’s a bit more involved than putting a hole in a round with a drill press but still.

That hole is there to create a weakness.

Overhead Hollow Point Comparison, ar15.com Molon
Overhead Hollow Point Comparison, ar15.com Molon

That weakness causes resistance when it hits something squishy and that resistance causes the bullet to start expanding.  That expansion is the key point.

Remember Newton’s Law: energy cannot be created or destroyed, only transferred.  With the expansion, the majority of the energy from the shot gets dissipated into the thing what you shot.

Ideally, this results in a much larger wound cavity and no exit wounds meaning the bullet stops inside the body.  Chance being what it is, that doesn’t always happen exactly as planned but there it is.

147 Federal HST Expansion
147 Federal HST Expansion

To finish up here, I want to take a moment to explain what a hollow point isn’t.

First off, it’s not some magical death talisman.  Aside from how Hollywood likes to portray them, the person isn’t going to go flying across a room if you so much as graze their shoulder.  All it means is that this bullet is going to impact a bit harder and probably not punch all the way through someone.  If it does go through, it’s probably not going to have much power after that.

It’s also not a “cop killer” round as some like to paint it.  Even low-end body armor is far more likely to stop a hollow point than it will an FMJ round.

Finally, barriers and such aren’t going to affect hollow points as much as you would think.

First off, they need a great deal of resistance to expand which the momentary contact with a barrier just isn’t enough to cause.  Mind you, it will start to expand in most cases but they’re made to fully expand via soft tissue contact.  Secondly, most hollow point rounds made in the USA are meant to satisfy the FBI Ballistic Test requirements.

They’re pretty extensive so I’ll just give you the Reader’s Digest version: gel penetration of a minimum of 12 to 18 inches through bare gel, heavy clothing, steel, wallboard, plywood, and glass.

5 Shots into Ballistic Gel
5 Shots into Ballistic Gel


Like I said in the beginning…FMJ for practice and hollow points for everyday carry and such.

Does that mean you should never practice with hollow points?

Heck no!

You need to know how your gun is going to react with that ammunition.  Guns don’t always like every bit of ammo you feed it.  Put at least a box or two through your gun when practicing but, beyond that, save yourself the money at the range.


16 Leave a Reply

  • Erica

    I’ve carried ball hollow points are both legal , only one tho g matters. Shot placement shot placement SHOT PLACEMENT ! I do find ball to be more accreted don’t get me wrong t as well hollow points leave larger holes and wind tracts So spend the money buy all the different brands of hollow points from. Blazer liberty is a very accurate. Round. I attribute. To its speed they shoot very well from my para ordnance ported made in Canada and x3 mod2 shoots them well toon have some 90s hornady +p that is too hot and all I’ve the place goes through 2 filled 5 gallon jugs and a Birmingham phone book ! Just my 2’ cents. Also unless they fixed it the Golden Saber loses its jacket, black talons and I know they have made better , liberty civil defence Goes about 1/2 to 3/4 into you amd acts like a grenade! Black talons although old school open CONSISTENTLY AND EVERY TIME ! I time to time load them but never chamber one to prevent nose shoving up and increasing pressures. So my warning shot is always ball ammo them my first shot would be if that terrible moment happens in my life. I’m sure it will be different than tv . But I do refuse to be a victim !!!!!!!

    1 month ago
  • Mdnypd

    As a former NYPD officer and I came across two suspects who are both shot with a 9 mm FMJ. One had three shots to the stomach area and buttocks station telling me he been shot. The second was a gentleman who shot 19 times with a 9 mm FMJ and still continue to resist with his AR 15. I’ve been shot at many a times with a 9 mm and it did not puncture my squad windshield. I can say with a high degree of certainty fmj rounds do not have any purpose for use in the field.

    1 year ago
    • Youhavenoideawhatyouretalkingabout

      I call BS on your story and I also call BS on your claim that 9mm never punctured your windshield. Caliber and bullet type wars are meaningless for handgun platforms and no matter how many times even the ammo manufacturers try telling us this (based on, you know, decades of testing with millions of shots fired and extensive analysis of FBI statistics) we still have ignorant chumps like you spreading misinformation and stories.

      1 week ago
  • Viictor

    If you want to stop a threat with your gun, you need to follow some steps, The shot placement is the first thing that have to think about. The second is tears much tissues as you can, to increase the chance to cause internal bleeding and dropping the blood pressure quickly or hit on CNS. A gun fight probably will not happend in the ideal conditions, because the threat may be on the side, with arm in front of his chest, may be behind a car door or window and wearing heavy clothes. So in my opnion, FMJ is better, because it will penetrate these objects in almost all cases and it will still hit the body.. On the other hand, hollow points may not expand in all cases and it will work as a bad fmj, or it may expand early and not have enough penetration to cause as many tissue tears as possible. But if you find a hollow point ammunition that expands in any kind of situation with absolute certainty, use it. But since I don't know anything like that, I prefer FMJ. Even if the fmj ammunition goes beyond the threat, which is unlikely, and hit someone, the energy is so small that at most it will scratch the skin. Hit the shots is better than worrying if you will use HP or FMJ, because if you think about the collateral damage that will cause if it does not hit the threat, this concern will also exist with HP ammunition. Dr Vicent Di Maio and Dr Martin Flacker have said they have never seen any cases where the victim was killed with HP ammo that would not be killed either by FMJ ammo. The truth is that companies make commercial advertisements for HP ammo as if they were magic or as if they were the best solution, they make beautiful, personalized boxes and sell something that promises to be infallible. The great truth is that they are more expensive, generate more profits and that lay public buy without thinking twice.

    1 year ago
  • Dan

    For every action, there is an equal and opposite reaction. The action is shooting the gun. The force of the bullet hitting the target will be equal to, or more likely, less than the recoil of the gun. There isn't going to be as much energy being transferred to the target as people think.. Most damage will be caused by the holes made by the bullets as opposed to the force transference. HP bullets will transfer a bit more power to the target by increased friction and expanding the force of the shot over a greater diamater, but most of the damage will be from the bigger hole and more shrapnel being left in the target.

    1 year ago
    • David

      The rough energy is equal-ish in both directions, but the force of the bullet on the target will be far, far, FAR more than the recoil of the weapon. The energy of recoil is dampened by the mass of the gun itself, the friction coefficients of the locking system, the ergonomics of the weapon and how the force transfers to the shooter, and a few other factors. Thus how you can have firearms with only a few foot-pounds of recoil. The bullet, on the other hand, is for one thing concentrated in a smaller area, thus for the energy is concentrated and gives it much higher foot-pounds. Bullets also have much less friction working against them since they are only passing through air and modern bullets are designed with this in mind, ie. Spitzer, low drag metal, smooth, etc. All of this to say - recoil rarely exceeds double digits foot-pounds in a handgun whereas the energy of the bullet is measured in the several hundreds of foot-pounds at least.

      1 year ago
  • Doug

    Damn good discussion !!

    1 year ago
    • Eric Hung

      Thanks Doug!

      1 year ago
  • Burp Gunner

    The companies need to start making jacketed soft flat tip amminition en masse' That would mean the Bubba Diet Root Beer crowd afford something reasonably effective in home defense, too.. Also Remington ammunition quality control has failed me twice recently. of 200 JHP 9mm Luger rounds purchased, ten were defective upon inspection. Privi Partizan, PMC, Federal, and Fiocchi donot have this problem. also. Question: is expanding metal jacket ammunition[EMJ] a good choice for defense, too?

    2 years ago
    • Eric Hung

      Hey Burp, I haven't had experience with EMJ's. What gun were you using that didn't like the Rem ammo?

      2 years ago
  • Dominic Licavoli

    A lot of great points here. Both rounds have advantages and disadvantages. If you have a threat that is using concealment a fmj round would be better depending on the concealment. I like alternating my rounds. So my magazines contain fmj and jacketed rounds alternating every other round. Best of both worlds because threats will not always stand out in front of you. Just food for thought. Not trying to be right.

    3 years ago
    • Rick in MI

      Dominic, while I don't necessarily disagree with your logic, before ANYONE staggers their ammo (FMJ, JHP, FMJ, JHP, FMJ, etc.) I STRONGLY suggest that they first test a few boxes of these exact ammos in the same order.. After testing this way, they then should load their magazines the same way using ammo from the exact same "lot" they've tested -- and if necessary test from these exact same boxes also. The reason is that a lot of semiautomatics (especially the smaller calibers) can jam rather easily -- either before, after, or during a shot.. While this is never an issue with my Colt 1911 in 45acp or my Sig Sauer in 9mm, the guns I'm most likely to have in my pocket or waist (a Seecamp .32acp or a Sig Sauer P232 in .380) both can be somewhat picky on ammo. (And my Seecamp only shoots 3 brands of JHP.) Because of this, I load these guns only with ammo that I know they like... and even then I still load only with lots I've previously tested.. I should also add that my SHTF car gun is a cheap Russian Makarov that shoots every .9x18mm round I can find to put in it, along with shorter (9x17mm) .380 rounds, if necessary. (And, frankly it will cycle a 9mm Parabellum/Luger round also, but I've never felt the urge to see if it would shoot one...mostly because I'm concerned the higher pressures of 9mm might break the old firing pin. BUT, if SHTF truly, and a bad guy was coming at me, I would have no problem dropping a 9mm round into the chamber if I thought 1 shot would put him down!)

      1 year ago
    • ehung

      Thanks for the insight Dominic...I've heard of that method for shotgun but never for pistol!

      3 years ago
  • Ray F.

    I respectfully disagree. Not with the physics, Don. Not with the physics, but with the evaluation of effectiveness. Caliber debates (which essentially the same as HP vs FMJ) never end because the goal post gets shifted. One person argues killing ability, another person argues knock down power, another argues military application, etc. In civilian human on human engagement, the only goal is stopping the opponent as fast as possible. Not killing, or critically wounding, but stopping the opponent. <br /> <br />With proper penetration, proper placement (as has been cited) is the primary stopping characteristic. The further you get from proper placement, the bigger your projo needs to be to stop the opponent. since the energy being absorbed by the target, at best, is less than the energy being released by the shooter, the transfer of energy doesn't have a quantifiable impact on stopping the opponent. <br /> <br />The only thing expansion provides is a bigger hole, which facilitates incapacitation through the more likely chance of hitting a vital or creating a quick bleed out. Unless you're hitting brain stem and turning out the lights, the bigger the hole that is required and an exit wound helps even more. Over penetration is a civil concern...not a stopping power concern. The more leaking holes, the better, hence the ability to control/properly place and quickly follow up three head or center mass .380 FMJ rounds at 15ft has a far better chance of stopping your opponent than a single HP .10mm to the left shoulder.

    4 years ago
    • Jason

      Ray, I think we're over thinking it, yes placement is key but look at it this way. Poke the palm of your hand with your pointer finger, That;s the FMJ. Now punch the palm of your hand. that's the HP. . That's the energy transfer. A FMJ is a pinpoint of force, the HP once expanded puts a larger amount if force because it doesn't just pass thru like a FMJ. I'm not saying a FMJ can't take down an assailant when a perfect shot is fired, but in a altercation because of adrenaline rush you might be slightly off. That's where the extra energy transfer may help you out. A fist to the chest is better than a finger to the chest.

      2 years ago
      • Dan

        I always carry a ruger plc11 380 with FMJ ammo. Sometimes I think shooters just don't think. They see all the different hollow point hydro shock etc and bite on it like bait. on a low caliber 380 etc. the last thing you want is for that bullet to do mis spread . . Penetrate and make the kill. Dan Ret. UASF

        1 year ago
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