“The well-known mouse gun caliber or the .32 ACP is the product of one of the firearms inventions greats” — John Moses Browning (1825 – 1926)
Developed in 1899 to be used in the FN Browning M1900 single-action semi-automatic pistol, and later for the FN Model 1903 or Browning No.2 pocket pistol, the .32 ACP is the most favored semi-automatic pistol cartridge of its time in the world.
Over the years, a great number of handguns were chambered for .32 ACP, and — even though it was considered to be less powerful by American caliber standards — in Europe, it was widely accepted with law enforcement organizations and armies through the 20th century.
Is 7.65 Browning the Same as .32 ACP?
This caliber was very popular in Europe, but it was known as the 7.65mm Browning.
But are the two calibers identical?
While their cartridges are dimensionally the same, the 7.65mm European ammo was loaded to a higher pressure. Why is this important?
If you’re using a 7.65mm Browning-chambered semi-automatic handgun with .32 ACP ammo you could experience jamming issues, as the 7.65mm pistol has a more powerful mainspring for handling higher pressure cartridges. An issue that can be solved by gunsmith reducing the mainspring.
Are .32 Auto and .32 ACP the Same?
Yes, they are the same. The “ACP” stands for “Automatic Colt Pistol.”
.32 ACP is also known as “.32 Automatic” or “.32 Auto” for short (mainly in America).
Other synonyms are:
- .32 Rimless Smokeless
- .32 Browning Auto
- 7.65x17mm
- 7.65 Walther
- 7.65x17mm Browning SR (Semi-Rimmed)
- 7.65mm Browning Short
Specifications of .32 ACP Ammo
.32 ACP is a centerfire pistol cartridge; its primer is located at the center of the casing’s base.
It’s semi-rimmed with a straight-walled cartridge. This second feature is required for a blowback operation — the self-loading of the pistol from the movement of the cartridge case being pushed back by the expanding gas created by the ignition of the charge.
The semi-rimmed part of the cartridge provides no interference for ammo feeding from a magazine, and the rim of the cartridge ensures ammo headspacing (stopping deeper cartridge barrel insertion).
The .32 Auto is considered by some to be a weaker round with less stopping power because of its specifications. But the fact remains that it has been effectively used by law enforcement and militaries worldwide for the past century.
This round is intended for the human-sized target and not hunting or vermin control, as its fixed sights are intended for closer range engagement.
It’s also commonly used in veterinary work as a “humane killer” and for the humane slaughter of livestock.
Now let’s take a look at some of its specifications:
| Case type | Semi-rimmed, straight |
| Bullet diameter | .3125 in (7.94 mm) |
| Neck diameter | .3365 in (8.55 mm) |
| Base diameter | .337 in (8.6 mm) |
| Rim diameter | .358 in (9.1 mm) |
| Rim thickness | .045 in (1.1 mm) |
| Case length | .680 in (17.3 mm) |
| Overall length | .984 in (25.0 mm) |
| Primer type | Small pistol |
| Maximum pressure | 20,500 psi (141 MPa) |
Ballistic Performance
The .32 Auto bullet type selection is limited to the standard full metal jacket, jacketed hollow point, and lead projectiles. But, there are some newer bullets — like all copper hollow point TAC-XP and Xtreme Cavitator solid copper rounds.
You can see the typical bullet’s grain and their ballistic performances below:
| Bullet type | Velocity | Energy |
| 60 gr JHP | 1,100 ft/s | 161 ft-lbs |
| 65 gr JHP | 925 ft/s | 123 ft-lbs |
| 73 gr FMJ | 984 ft/s | 158 ft-lbs |
| 73 gr FMJ | 1,043 ft/s | 177 ft-lbs |
What interests us is this — how does it perform in a real-life situation?
The closest we get to the real-life scenario is the FBI standard ballistics gel penetration test — depth from 12 to 18 inches is required to reach vital organs.
Can .32 Auto do that? Yes, it can — but it doesn’t mean it will.
So, with that uncertainty in mind, let’s answer the following question.
Is .32 ACP Good for Self-Defense?
Although the .32 ACP is known as a mouse gun caliber, we can’t ignore the fact that any caliber can inflict serious and potentially deadly injuries.
It may not be the best choice when facing an attacker wearing body armor or when firing at a target more than 15 yards away — even at closer distances, its efficiency is a matter of accuracy.
But guns chambered in .32 Auto have little recoil, which gives the shooter more accuracy. And at the right distance (5 yards and closer), the .32 ACP can penetrate the skull.
So is it a perfect self-defense choice? No.
But is it good enough? Let’s put it like this: A warning shot will make the attacker think twice, and used at a close enough distance, it’ll be efficient and deadly.
If you still have doubts, consider this. If it was good enough for the most known movie spy in the world — James Bond, who carried a Walther PPK — then it’s good enough for our small caliber back-up gun or concealed carry weapon (CCW).
What Are the Best .32 Caliber Pistols?
Even though the peak of the pocket pistols’ popularity was during the 20th century, they are still great sellers and are a favorite back-up pistol or a CCW choice.
Here is a shortlist of the best pistols chambered in .32 ACP:
- Beretta 3032 Tomcat
- Colt 1903 Pocket Hammerless
- Kel-Tec P-32
- Remington Model 51
- Walther PPK
Will .32 Auto Work in a Revolver?
Yes, but you might want to think twice before using it. The .32 ACP wasn’t designed for revolvers, but semi-automatic handguns.
As we mentioned, .32 ACP has a semi-rimmed cartridge, making it different from other semi-automatic rounds. Chambering it in a revolver will be the first issue you’ll have — the rim will hold the cartridge in place instead of slipping down the chamber.
Because of that, the cases can get stuck. You won’t have much trouble getting them out, but enough to become irritating.
Another issue is that it will not be very accurate. The .32 ACP bullet is a bit smaller than the .32 revolver bullet, so projectiles won’t stabilize enough while traveling down the cylinder, causing it to tumble and be less accurate.
Finally, the slight difference in size between the .32 ACP and the .32 revolver cartridge means that there will be some unwanted and potentially dangerous space between the primer and the striking pin.
This can lead to malfunctions — from a misfire to a potentially dangerous piercing of the primer, causing pressure gas to escape back to the shooter.
So, our advice is it’s better not to do it.
Time to Pull the Trigger
Are you low on your .32 ACP ammo, or ready to give it a try for the first time?
We’ve got you. Visit our online store at BulkMunitions and order today.
We sell in bulk and ship within 48 hours. The ammo will be at your doorstep in about 1–4 days, so you don’t have to trouble yourself with anything but finding even more time to enjoy backyard plinking or shooting at the gun range.
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Consider becoming a repeat customer. We have a special membership that will save you even more money when you buy ammo from BulkMunitions.
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Don’t wait — order your .32 ACP today, as these days ammo quickly goes as soon as we have it in stock.
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Featured Image: Pixabay by MikeGunner
