Is it time to open the “Is .32 enough” debate?
They have already opened is .22 enough!
This guy I know from work has a CCW. He doesn’t carry. Why? He’s got a .50 and cannot conceal it.
Kid you not, actual conversation.
So there is an argument that the 9mm luger has more “stopping power” than 380 ACP. If we are thinking about stopping power in terms of ability to stop an individual in a defense situation there are obviously tons of reasons to pick one cartridge over another. The one I come across most is that the 9 mm can stop someone easier because it has more kinetic energy and is a bigger bullet. Keep in mind that the diameters are the same it might not make a huge difference in the entry hole. The difference I could see without digging insanely deep into the math and keeping it simple is that 9 mm is a more energetic round (see figure 1.). Because the 9 mm bullet fires with more energy and because hallow point work by trapping air in the pit of the front and the individuals body, there would be more force transferred from the trapped air to the body than the 380 ACP round.
If this causes more damage it is reasonable to assume there is a higher chance of stopping an individual.
The size of the pit in hallow points will also vary greatly and it may be more than just the trapped gasses that cause it to peel open.
So, with that in mind the question of does it have more stopping power? I would say yes but it depends on more than that. Can you control a 9mm as well as a 380 ACP in a bad situation with a bad shoulder or other muscle issue that will change how you aim? Will you practice less if the round hurts you too much? What makes the most sense for you may vary. Personally, I use a 380 ACP and I have been considering getting a 9 mm. I haven’t yet because I struggled to find a 9mm sub compact in stock. Its all up to you of what you deem is more important in protecting yourself.
I hope this isn’t full of mistakes but please let me know if you have differing opinions on this topic and my approach was flawed. Constructive criticism only please.
Kinetic Energy (KE) Equation: KE = .5mv^2
9mm bullets are 9mm in diameter, usually weigh ~150 grain, and runs travels about 850fps.
KE = 0.00971984kg*(259.08m/s)^2
652.4 joules of energy
380 bullets are 9 mm in diameter but slightly shorter, weigh ~100 grain and travel roughly 1000 fps.
KE = 0.00647989kg*(304.8m/s)^2
602.0 joules of energy
Keep in mind these are rough calculations and different loads will vary a lot. I just threw this together to put my thought process down.
Please keep in mind this is for self defense and the most popular self defense rounds are hallow points. Take a look at my comment below. Thank you for the diagram it’s good information as well.
Stopping power is more correctly associated with momentum, mv, not kinetic energy, mv-square. Not having that square power means much more gentle increase in stopping power from caliber to caliber. According to Ammo Momentum and Energy Chart | Ruger Forum , difference in momentum between a 380 at 90grn, and a 9mm at 115 grns is 6 lb-ft/s, while overall momentum of 9mm is 19 lb-ft/s.
Imagine hanging a 5lb dumbbell and a 20 lb dumbbell on a wire at chest height, and then casually walking into them. Much stopping power?
When it comes to stopping power, the 380 makes the FBI’s defensive round list. Just as 9mm rounds have more versatility today, so does the 380…and why not? It used to be called a “9mm short” years ago.
I have a daughter that has a Walther PK 380…a very nice gun. I’m gonna probably make my next purchase a Walther PPQ 9mm and then I’ll get a Bersa Thunder 380. I think I’m done after that.
Here’s a pic of my daughters Walther:
Yep Shot placement!