Guns & Ammo by ohn Taffin
If there were ever two handgun cartridges that could be classified as ubiquitously American, then it would be the 45 Long Colt and the 45 Automatic Colt Pistol (ACP). With a combined service life of over two centuries, both have served as the sidearm cartridge for the U.S. Army and are still used in various applications today in civilian circles.
Although the 45 Colt and 45 ACP have similar naming conventions, they are not interchangeable and are used in completely different firearms. The 45 LC is predominantly a revolver cartridge while the 45 ACP is used in semi-automatic handguns.
In this article we will compare two of the most iconic 45-caliber handgun cartridges in American history so that you can have a deeper understanding of each and what makes them an excellent choice for your next firearm purchase.
Table of Contents
• What is The Difference Between 45 Long Colt vs 45 ACP?
o Cartridge Specs
o Stopping Power/Kinetic Energy
o Recoil
o Velocity/Penetration
o Magazine Capacity
o Hunting
o Concealed Carry/Home Defense
o Ammo and Handgun Cost/Availability
o Reloading
• Ballistics: .45 Long Colt vs .45 ACP
o .45 Colt Ballistics
o .45 ACP Ballistics
• .45 Colt Development and History
• .45 ACP Development and History
• Final Shots: .45 Colt vs .45 ACP
What is The Difference Between 45 Long Colt vs 45 ACP?The difference between 45 Long Colt and 45 ACP is the case design and the original powder used in each cartridge. The 45 Long Colt is a rimmed revolver round designed to use black powder while the 45 ACP is a rimless cartridge designed for use in semi-automatic pistols with smokeless powder.
Cartridge SpecsWhen comparing two handgun rounds, it’s a good practice to examine the cartridge specs to gain a better understanding of each.
Perhaps the most obvious difference between the 45 Long Colt (LC or Colt for short) and 45 Auto is their case length. The 45 LC has a case length of 1.285” compared to 0.898” for the 45 ACP. The overall length of the 45 Colt is also longer at 1.6” compared to 1.275” for 45 Auto.
With a longer case, it’s no surprise that the 45 LC has a higher case capacity than the 45 ACP. The 45 LC case can house upwards of 41.6 grains of propellant compared to 26.7 gr for the 45 Auto.
Although the 45 Long Colt can handle over 50% more powder than the 45 ACP, the 45 LC has a lower maximum pressure of 14,000 psi compared to 21,000 psi for 45 ACP as established by SAAMI. This is perhaps one of the biggest differences between the two cartridges: the 45 Colt cartridge was designed to use black powder while the 45 ACP was designed to be fired with smokeless powder.
As black powder produces considerably less pressure than modern smokeless powders, extreme caution needs to be observed when using modern 45 Long Colt cartridges in classic revolvers. As these revolvers were not designed to handle the higher pressures modern ammo can produce, a catastrophic failure might result causing damage to the firearm and potentially the shooter.
It should also be noted that the bullet diameter is the same for both cartridges. The cast lead bullet diameter is used in the table above of 0.452”, full metal jacket (fmj) or jacketed hollow point (jhp) bullets will have a diameter of 0.451” for both cartridges.
Although both handgun rounds fire the same diameter bullet, the 45 Long Colt will generally fire heavier bullets as it was designed to fire a 250 gr cast lead bullet while the 45 ACP was developed using the 230 gr fmj bullet in mind.
The 45 Long Colt can fire bullets between 180 and 335 gr, with the 225 and 250 grain bullets being the most popular. In contrast, the 45 ACP can fire bullets between 135 and 250 gr with the 185 and 230 gr options outstripping all other factory loads.
More:
https://ammo.com/comparison/45-colt-vs-45-acp