Difference Between ACP and Auto (With Table)

It is important not to confuse the Auto pistol with the ACP because they are incredibly different from inefficiency and other technical criteria. There are two automatic pistols: fully automatic guns and semiautomatic pistols.

The term auto refers to ‘automatic,’ and there are two automatic pistols. There are many distinctions between an ACP and an Auto pistol, and this article will discuss the variations in attributes between an ACP and an Auto pistol.

ACP vs Auto

The main difference between ACP & Auto is that ACP stands for Automatic Colt Pistol, whereas Auto means automatic; on the other hand, there does not appear to be much of a distinction between the two terms.

However, in terms of technology, the ACP is primarily used by army members, whereas the Auto is used in rescue missions, secret expeditions, etc. The ACP rounds, in addition, have a larger diameter than the projectiles used in the Auto, which is a significant difference. As a result, the penetrating force of the bullet is increased, making ACP handguns even more dangerous.

The term “Automatic Colt Pistol” (ACP) refers to a variety of John Moses Browning ammunition types primarily used in semiautomatic handguns manufactured by the Colt and Fabrique Nationale de Herstal companies. These bullets are all straight-sided and have a uniform appearance. The.25 ACP and.32 ACP, with a rim-free, and 45 ACP gaps on the case’s opening are the most common calibres.

These ACP bullet-powered pistols are mainly employed for tactical and military activities since they provide a significant amount of firepower for their size. For its tiny size and high efficiency, the Auto, on the other hand, is more well-known. When the ammunition runs out or the trigger is pulled, the Auto pistol will continue to shoot. An automatic pistol is a simple sort of repetitive firearm (gun) that mechanically cycles its action to place the next round of ammunition into the barrel (self-loading). Still, it requires the user actuation of the hammer to discharge the next shot.

Comparison Table Between ACP and Auto

Parameters of ComparisonACPAuto
Full-FormAutomatic Colt Pistol is the abbreviation for ACP.  Automatic handguns are referred to as Autos.  
UsageIt is ideal for military and covert operations because of its lightweight and great accuracy.  The bullet’s speed eventually exceeds that of a rescue vehicle, although it can still be a viable alternative for hunting.  
RoundsThe ACP ammo has a broader diameter than that of the autos.  For example, the 9mm auto round has a smaller diameter than, say, the.45 ACP round.  
Penetrating PowerEven from 10 to 15 yards away, a shot to the chest can kill a person, even if it’s just grazed.  Bullets that are lighter and smaller in diameter have a less penetrating power.  
Meaning and ExamplesACP refers to a variety of John Moses Browning ammunition types used mainly in semiautomatic pistols manufactured by the “Colt” and “Fabrique Nationale de Herstal” companies.  As the name suggests, an auto pistol looks like a handgun. Skorpion and the P18C, often known as Glock 18C, are great examples.  

What is ACP?

When John Moses Browning designed the ACP (Automatic Colt Pistol) or.45 Auto (11.4323mm) ammo in 1904, he was using it in his experimental Colt semiautomatic handgun, which he called the Colt. In the aftermath of successful military tests, it was determined to be the official chambering for Colt’s M1911 handgun and was awarded the designation as such. 45 ACP (automatic pistol).

In contrast to the Auto pistol, the ACP is a semiautomatic pistol. The ACP is a relatively safe bet to make in the long run. It is well-known for always being highly precise, mainly when applied to humans. The use of this weapon is highly recommended for aggressive purposes in situations requiring quick skill and agility.

An additional advantage of this weapon is that it produces very little noise, and it is fitted with an outstanding noise suppressor that significantly suppresses background noise levels. Compared to other guns in the same class, the maximum chamber pressure is 145 MPa, which is extremely low compared to other guns.

The permeability of shots fired from an ACP pistol ranges from 11 to 27 inches, depending on the route along which the cartridge is discharged and the shooter’s accuracy.

Colt has manufactured several self-loading handguns. First, it was the Colt M1900, which was produced exclusively for the military from 1900 to 1902. It was the first of its kind. Ammunition for this pistol was in the form of the ACP 38 cartridge. For the same purpose, the Colt Model 1903 Compact Hammer was created. Between 1902 and 1928, the 38 ACP cartridge was available.

What is Auto?

‘Auto’ The term “automatic” is used only infrequently in the context of handguns; nonetheless, there are 9mm automatic handguns with optional extensions, such as the military-grade P18C, better generally known as the Glock 18C, whose automatic trigger release and shoot makes it challenging to handle for beginners.

The auto.45 is almost the same if we’re talking about ammunition.45 ACP, but its compatibility with automatic pistols elevates the designation to something special.

When the duelling parties are brought into close contact, the Auto is called upon to assist them. This small weapon is easier to wield and operate indoors and in confined spaces because of its small size. Some bullet cartridges go by a variety of names. Several of them have so many that a novice shooter may be concerned about whether or not they are purchasing the correct ammunition.

In firearms, an auto-loading gun (sometimes known as an ‘auto’) is a firearm that charges and shoots cartridges continuously when the trigger system is depressed. An automatic firearm’s operation can absorb additional energy from a previous discharge and use that energy to load a new ammunition cartridge into the barrel, ignite the fuel, and shoot the bullet.

Main Differences Between ACP and Auto

  1. In this case, ACP is an acronym for Automatic Colt Pistol, while Auto is an abbreviation that stands for an automatic pistol.
  2. When comparing the two kinds of handguns, it is more frequent to encounter ACPs than to encounter automatic pistols.
  3. The Glock 18C is a semiautomatic handgun used in military operations in the.45 ACP calibre, while search and rescue missions use automatic firearms like the Glock 45 ACP.
  4. Bullets for automatic pistols have a lower diameter than ACP rounds, which have a larger diameter.
  5. In this circumstance, it is the favoured alternative since it has double the penetration strength of the Auto.


For self-defence, the ACP is a superb option. When it comes to general target shooting, the.45 ACP bullets are a better choice than the 10mm. On the other hand, the Auto is the clear winner when hunting with a pistol. It uses a lighter bullet with a greater rate of fire than the ACP, but accuracy and penetration are sacrificed. As a beginner, the ACP is an excellent choice.


  1. https://academic.oup.com/humrep/article-abstract/19/6/1461/2356516
  2. https://www.sciencedirect.com/science/article/pii/S0008621516302440