Are you confused about the differences between 380 Auto and 380 ACP ammunition? Look no further! In this article, we will break down the history, development, caliber specifications, performance comparison, availability and cost, firearm compatibility, personal defense considerations, and legal considerations of these two popular rounds.

Whether you are a seasoned gun enthusiast or a beginner looking to purchase your first firearm, understanding the distinctions between these two calibers is essential. Stay tuned to learn everything you need to know about 380 Auto and 380 ACP!

Key Takeaways:

  • 380 auto and 380 ACP are two different calibers, with 380 auto being the longer and more powerful version.
  • 380 auto and 380 ACP have different histories and development, with 380 ACP being the older and more popular option.
  • When it comes to personal defense, both calibers have pros and cons, including differences in ballistics, stopping power, and availability. It is important to consider these factors when choosing the right caliber for your needs.


Understanding the difference between .380 Auto and .380 ACP is essential for firearm enthusiasts and those interested in ammunition.

While many people use the terms interchangeably, there is a subtle distinction between the two.

  • .380 Auto, also known as 9mm Short, is a cartridge designed for semi-automatic handguns.
  • On the other hand, .380 ACP, which stands for Automatic Colt Pistol, is a rimless, straight-walled pistol cartridge introduced by John Browning in 1908 for the Colt Model 1908 Vest Pocket.

Both these calibers have gained popularity for their compact size, making them ideal for concealed carry and self-defense applications.

Understanding the Differences between 380 Auto and 380 ACP

The distinction between 380 Auto and 380 ACP lies in their design, ballistic characteristics, and historical development, attributed partly to the innovative work of John Moses Browning.

380 Auto, also known as 9mm Browning Court or 9x17mm, was designed by John Browning in 1908 for the Colt Model 1908 pocket pistol. This round delivers adequate stopping power for concealed carry purposes. On the other hand, 380 ACP (Automatic Colt Pistol), introduced in 1908 by Colt, is slightly shorter than 380 Auto, suitable for small, compact firearms. Known for its manageable recoil and accuracy, 380 ACP is a popular choice for self-defense applications.

History and Development

The history and development of .380 Auto and .380 ACP are intertwined with the evolution of calibers like 9mm and the intense caliber war documented in Cartridges Of The World.

Both the .380 Auto (also known as the 9mm Browning Short) and the .380 ACP (Automatic Colt Pistol) have interesting historical roots that date back to the early 20th century. While the .380 Auto was developed by John Browning in 1908 for the Colt Model 1908, the .380 ACP was introduced by Colt in 1908 as well, making it a significant year for the development of these calibers. Their introduction marked a shift towards compact and more concealable firearms, influencing the design and production of small, semi-automatic pistols.

In the broader context of caliber developments, these calibers played a crucial role in bridging the gap between larger handgun calibers and smaller, less powerful rounds. The .380 Auto and .380 ACP provided a balance of manageable recoil and adequate stopping power, which appealed to many gun owners looking for a reliable self-defense option.

Caliber Specifications

Exploring the caliber specifications of .380 Auto and .380 ACP involves understanding elements like headstamps, cartridge mouths, rims, and considerations for indoor range use.

When examining .380 Auto, you’ll notice headstamps typically carry markings denoting the manufacturer and caliber. The case mouth of a .380 Auto cartridge has a slight taper, aiding in smooth feeding and extraction. The rim of this cartridge type is generally rimless or semi-rimmed, enhancing reliable chambering.

In comparison, .380 ACP headstamps often display the caliber and occasionally the manufacturer. The case mouth of a .380 ACP cartridge is usually straight, promoting proper alignment in the chamber for accurate shooting. This caliber typically features a rimless design, facilitating seamless cycling in semi-automatic firearms.

In terms of indoor shooting ranges, both calibers are popular choices due to their manageable recoil and moderate power, making them suitable for practice and training sessions without excessive noise or recoil impact.

380 Auto

The .380 Auto, also known as .380 ACP, is a popular choice for pistols and revolvers, offering a compact alternative to larger calibers like .45 Auto and .45 ACP.

Despite its smaller size, the .380 Auto packs a punch, making it ideal for self-defense applications due to its manageable recoil and sufficient stopping power. Many shooters appreciate the lighter weight and ease of concealment provided by firearms chambered in .380 Auto, making them popular for everyday carry or as backup weapons.

Compared to larger calibers such as .45 Auto and .45 ACP, the .380 Auto offers reduced recoil, allowing for quicker follow-up shots and greater control, especially in compact and subcompact handgun models.

380 ACP

The 380 ACP, a.k.a. 9mm Corto, 9mm Ultra, 9mm Makarov, and 9mm Long Colt, offers a diverse range of ammunition choices for firearms enthusiasts and collectors.

Each of these variations possesses unique characteristics, catering to different preferences and needs in the world of handguns and firearms. While the 380 ACP is widely recognized for its compact size and moderate recoil, the 9mm Corto stands out for its historical significance and reliability. On the other hand, the 9mm Ultra is favored for its increased velocity and energy, making it a favored option for self-defense applications.

Performance Comparison

Comparing the performance of .380 Auto and .380 ACP involves analyzing factors like muzzle flash, noise levels, stopping power, and considerations for tactical flashlight use.

In terms of .380 Auto vs .380 ACP performance, understanding the differences in muzzle flash is crucial. .380 Auto tends to produce a brighter muzzle flash compared to .380 ACP, which may have implications for low-light shooting situations.

In terms of sound intensity, while both calibers are known for being relatively quiet, .380 Auto generally produces a slightly sharper noise due to its higher pressure levels.

Stopping power is another vital aspect to consider, with .380 ACP often being favored for its deeper penetration and better ability to incapacitate a target. This underscores the importance of shot placement and the use of tactical flashlights in enhancing visibility and target identification.


The ballistics data of .380 Auto and .380 ACP can be compared to other calibers like .32 New Police, .38 New Police, and .40 Auto to assess their performance in various shooting scenarios.

When analyzing the ballistics of different calibers, it’s essential to understand the nuances of each round. .380 Auto, also known as 9mm Short, and .380 ACP, short for Automatic Colt Pistol, are popular choices for self-defense due to their manageable recoil and decent stopping power.

In comparison, the .32 New Police is a less common cartridge, mainly used in older revolvers. The .38 New Police, a predecessor to the .38 Special, is known for its mild recoil. The .40 Auto, or 10mm Auto, offers a balance of power and controllability.

Stopping Power

Assessing the stopping power of .380 Auto and .380 ACP entails considering factors like headspace, case mouth design, rim dimensions, and their impact on terminal ballistics in indoor range environments.

In terms of .380 Auto and .380 ACP, understanding the intricacies of headspace is crucial. Headspace refers to the measurement from the base of the cartridge to the breechface when the round is fully chambered.

The case mouth design can greatly influence how the bullet engages with the rifling of the barrel, impacting accuracy and ultimately, stopping power. The rim dimensions of these cartridges also play a significant role in reliable extraction and ejection of spent casings, especially important in high-stress shooting scenarios.

Availability and Cost

Examining the availability and cost considerations of .380 Auto and .380 ACP involves analyzing packaging formats, bullet types like FMJ, and pricing structures in the ammunition market.

Within the ammunition industry, these two calibers, commonly used for concealed carry handguns, have distinct market presences. The .380 Auto, also known as the 9mm Kurz or 9mm Short, is favored for its moderate recoil and compact size, making it popular among individuals seeking a balance between stopping power and comfort. On the other hand, the .380 ACP, or Automatic Colt Pistol, offers similar performance but with historical ties to famed firearms like the Browning-designed Colt Model 1908. The variations in packaging, such as bulk packs or premium boxes, cater to different consumer preferences and shooting needs.

Ammo Varieties

The diverse ammo varieties of .380 Auto and .380 ACP showcase the intricate design nuances championed by John Moses Browning amidst the backdrop of the infamous caliber war.

In the realm of ammunition, .380 Auto and .380 ACP stand out for their compact yet impactful nature. These cartridges offer a balance of power and size that has made them popular among concealed carriers and those seeking a reliable self-defense round. John Moses Browning, a legendary firearms designer, played a pivotal role in shaping the design elements of these cartridges, emphasizing reliability, efficiency, and effectiveness.

The .380 Auto and .380 ACP cartridges are a product of the fierce competition during the caliber war era, where manufacturers constantly strived to create the most potent and reliable ammunition. As a result, advancements in bullet design, casing materials, and propellants were made to enhance the performance of these rounds.


The pricing of .380 Auto and .380 ACP is influenced by factors such as manufacturer choices, market dynamics, and the insights gleaned from Cartridges Of The World.

Manufacturers play a pivotal role in determining the cost of these popular handgun cartridges. Different brands often have varying production costs, which can directly affect the final price point for consumers. Market trends such as supply and demand fluctuations, changes in raw material prices, and even geopolitical events can impact the overall pricing strategy of these ammunitions.

By referring to resources like Cartridges Of The World, enthusiasts and collectors can gain valuable historical context on pricing trends, production volumes, and other factors that continue to shape the market for .380 Auto and .380 ACP.

Firearm Compatibility

Exploring firearm compatibility with .380 Auto and .380 ACP involves considering SAAMI standards, Automatic Colt Pistol designs, and the nuanced requirements of each caliber for optimal performance.

One critical aspect of firearm compatibility with .380 Auto and .380 ACP is the adherence to SAAMI standards. These standards ensure that the ammunition meets the industry-set specifications, such as pressure limits and dimensions, to guarantee safe and reliable performance in firearms designed for these calibers.

The influence of Automatic Colt Pistol design specifications on .380 ACP ammunition is significant. The original designs by John Browning aimed to create a reliable, effective round suitable for semi-automatic pistols, leading to the development of the .380 ACP cartridge.

When selecting ammunition for firearms chambered in .380 Auto or .380 ACP, it is crucial to choose the appropriate type that aligns with the specific requirements of the firearm model. Different guns may have varying tolerances and functionalities, necessitating the right selection of ammunition for smooth operation and accurate shooting.

Personal Defense Considerations

When contemplating personal defense choices, understanding the implications of .380 Auto, .380 ACP, and related calibers like 9mm Luger and Parabellum becomes paramount for well-considered choices.

These calibers are popular choices for concealed carry and self-defense due to their manageable recoil, compact size, and effectiveness in stopping threats. Many gun owners appreciate the balance of stopping power and ease of control that .380 Auto offers, making it suitable for shooters of varying experience levels. The availability of ammunition and firearms chambered in these calibers contributes to their widespread adoption.

When comparing .380 Auto to 9mm Luger, individuals often consider factors such as bullet weight, velocity, and penetration capabilities. Both calibers have their strengths, with 9mm generally offering higher muzzle energy and better penetration, while .380 Auto provides for a more manageable shooting experience with moderate stopping power.


The accuracy of .380 Auto and .380 ACP can be evaluated against benchmarks like 9mm Luger and Parabellum, examining design intricacies and ammunition performance for precision.

When comparing the design features, the .380 Auto and .380 ACP cartridges are slightly shorter but wider than the 9mm Luger, affecting their ballistic performance. The ammunition characteristics play a crucial role in determining accuracy, with factors such as bullet weight, powder charge, and muzzle velocity influencing shot placement and grouping.

While the .380 Auto and .380 ACP are popular choices for concealed carry due to their compact size and manageable recoil, they may not offer the same level of accuracy as the larger 9mm cartridges. Shooters often find that the 9mm Luger and Parabellum rounds provide better long-range precision and stopping power, making them preferred options for target shooting and self-defense scenarios.


Assessing the recoil patterns of .380 Auto and .380 ACP involves referencing SAAMI standards, analyzing design elements, studying ballistic data, and considering firearm specifics.

While both .380 Auto and .380 ACP are popular choices for concealed carry due to their manageable size and moderate power, their recoil characteristics differ subtly but significantly. The .380 Auto, also known as the 9mm Browning, is a rimless cartridge designed by John Browning. On the other hand, the .380 ACP, or Automatic Colt Pistol, was developed by John Moses Browning. These cartridges have similar dimensions but vary slightly in overall length, resulting in differences in chamber pressure and bullet weight.

When fired, the design nuances of .380 Auto vs. .380 ACP come into play, affecting how the energy is transferred to the firearm and subsequently to the shooter. The weight of the firearm, grip design, and overall construction play pivotal roles in how felt recoil translates during shooting. Understanding the ballistic data of these rounds further elucidates how velocity, bullet weight, and energy distribution contribute to the perceived recoil experience for the shooter. Pairing the right ammunition with a firearm that complements its design can significantly impact shooting comfort, accuracy, and overall handling.


The reliability assessments of .380 Auto and .380 ACP hinge on adherence to SAAMI standards, caliber-specific design considerations, and the quality of ammunition employed.

SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute) sets the performance specifications that manufacturers must meet for both .380 Auto and .380 ACP ammunition, ensuring consistency and safety in the industry. For .380 Auto, factors like case dimensions, pressure levels, and velocity are crucial for reliable functioning in firearms designed for this caliber. On the other hand, .380 ACP, with its slight variations from .380 Auto, requires specific attention to feed ramp design, recoil springs, and overall pistol construction to optimize performance and reliability.

Legal Considerations

Navigating the legal landscape around .380 Auto and .380 ACP involves understanding firearm regulations, Government Model specifications, historical references like M1911, and the influence of cases such as Mrs. Gump.

Understanding firearm laws is crucial when dealing with firearms such as .380 Auto and .380 ACP, as each state may have different regulations around ownership, carrying, and usage.

The Government Model, originally referring to the Colt Government Model 1911, has set standards for semi-automatic pistols in terms of design and functionality.

The historical significance of M1911 in the evolution of handguns cannot be overstated. Its design has influenced modern firearms and continues to be revered among gun aficionados worldwide. Legal cases like that of Mrs. Gump have highlighted the need for stringent laws and background checks to prevent firearm-related tragedies and illicit activities.

Concealed Carry Laws

Understanding concealed carry laws pertinent to .380 Auto and .380 ACP necessitates knowledge about caliber restrictions, firearm specifications like the Government Model, and considerations regarding muzzle flash effects.

Many states have specific regulations regarding the .380 Auto and .380 ACP calibers when it comes to concealed carry. For example, some states may have minimum caliber requirements for self-defense use, which could impact the legality of carrying a firearm of this size.

The design and size of firearms, including those based on the Government Model, play a crucial role in how they are classified and permitted for concealed carry. These specifications can dictate whether a firearm is deemed suitable for everyday carry or if it falls outside legal boundaries.

Muzzle flash control is another critical aspect that carries weight in determining the permissibility of certain firearms. Factors like barrel length, ammunition type, and built-in flash suppressors can significantly influence how much muzzle flash is produced, potentially affecting the user’s safety and concealment ability in various environments.

Self-Defense Laws

Self-defense laws pertaining to .380 Auto and .380 ACP demand an understanding of SAAMI standards, caliber-specific design considerations, and the implications of using particular ammunition types.

In terms of self-defense scenarios, knowing the distinctions between .380 Auto and .380 ACP can significantly impact legal ramifications. Both calibers adhere to the standards defined by the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI), ensuring safety and consistency in performance. However, design factors such as bullet weight, velocity, and bullet type play a crucial role in determining how each caliber performs in real-life situations. Consequently, selecting the right ammunition that meets SAAMI regulations is vital to safeguarding your legal standing in a self-defense incident.


The comparison between .380 Auto and .380 ACP reveals insights into their performance, historical significance amidst the caliber war, and the relevance of alternative calibers like 9mm Luger and Parabellum in the ammunition landscape.

When examining the .380 Auto and .380 ACP ammunition types, it is essential to delve into their ballistics and stopping power, as these factors play a crucial role in self-defense scenarios. The .380 caliber has a rich history, originating in the early 20th century, and has evolved significantly over time.

This comparison not only sheds light on the preferences of different gun owners but also highlights the ongoing debate surrounding caliber choices for concealed carry or home defense. The popularity of the 9mm Luger and Parabellum calibers underscores the diverse preferences and requirements of individuals within the firearms community, emphasizing the need for comprehensive understanding and well-considered choices.

Frequently Asked Questions

What is the difference between 380 auto and 380 acp?

380 auto and 380 acp are both popular names for the same cartridge, also known as 380 ACP (Automatic Colt Pistol). There is no difference between the two, they are just different names used by different manufacturers.

Which one is better: 380 auto or 380 acp?

As mentioned before, 380 auto and 380 acp are the same cartridge. Both are reliable and widely used, so it ultimately comes down to personal preference and the specific firearm being used.

Can a 380 auto be used in a 380 acp gun?

Yes, 380 auto and 380 acp are interchangeable and can be used in the same firearm. Just make sure to check the manufacturer’s specifications to ensure compatibility.

What is the history of 380 auto/380 acp?

The 380 ACP cartridge was developed by John Browning in 1908 for use in his Colt Model 1908 pocket hammerless semi-automatic pistol. It has since become a popular choice for self-defense and concealed carry.

Are there any differences in ballistics between 380 auto and 380 acp?

Both cartridges have similar ballistics, with an average muzzle velocity of around 950 feet per second and a muzzle energy of around 200 foot-pounds. However, specific performance may vary depending on the manufacturer and specific load.

Is 380 auto/380 acp a suitable choice for self-defense?

Many people consider 380 auto/380 acp to be a suitable choice for self-defense due to its manageable recoil and compact size. However, it is always important to practice and choose a high-quality ammunition to ensure effectiveness.

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