Difference Between 38 and 357 (With Table)

People obsessed with guns or who collect guns must have detailed knowledge about 38 and 357 cartridges. The 38 Special is a regular, commonly used cartridge in many revolvers. Sometimes it also gets used in carbines and semi-automatic pistols. 357 magnum has bullets 357-inch in diameter. Both can be identified and differentiated by gun experts and collectors.

38 vs 357 

The main difference between 38 and 357 is that the designers of 38 are Smith and Wesson, whereas 357 was designed by Elmer Keith Philip B Sharpe. The neck diameter of 357 is .379 for 9.6mm and 0.379 for 9.6mm in the case of 38. The 357 was designed in the year 1934, whereas the 38 was designed in the year 1898. Primer type of the 357 is generally a small pistol and magnum, whereas, in the case of the 38, it is a small pistol type only.

The case length in the case of 38 is 1.155 for 29.3mm. The overall length of 38 is 1.55 in 39mm. The base diameter is .379 in 9.6mm in the case of 38. The bullet diameter for 38 is 357 for 9.1mm. The rim diameter of 38 is 0.44 in 11mm. The .38 is a centerfire cartridge. Except for a few variations, 38 is mostly identical to 357. The 38 could be used in revolvers chambered for 357. This is why 38 is widely used in many revolvers.

The case length of 357 is 1.29 for 33mm. The overall length is 1.59 in 40mm. The base diameter is 357 in 9.6mm. The bullet diameter in the case of 357 is 357 for 9.1mm. The rim diameter of 357 is 0.440 in 11.2mm. 357, which is a centerfire cartridge. Apart from certain differences, the rest 357, is mostly identical to 38. 357 cannot be used in revolvers chambered for 38 cartridges.

Comparison Table Between 38 and 357

Parameters of comparison 38357
Designed byThis is designed by Smith and WessonThis is designed by Elmer Keith and Philip B Sharpe of Smith and Wesson
Launched Released in the year 1898Released in the year 1934
Case lengthCase length in 1.155 in 29.3mmCase length is 1.29 in 33mm
Maximum Pressure17,000 psi (121 Mpa)35,000 psi (240 Mpa)
Primer TypeSmall pistolMagnum (Small pistol)

What is 38? 

The 38 special revolver cartridge is most commonly used in carbines and semi-automatic pistols. It originated from the USA and was used as a standard service cartridge in police departments of the USA in earlier times. It was an improved and modified version of 38 long colt as a cartridge for military service. The production of 38 began in the year 1898. The 38 cartridges have a length of 357 inches which is opposite of its name.

Renowned for its accuracy and precision, this remains one of the most popular revolver cartridges of all time.38 special as identical parameters as that of 357 magnum, 38 short and long colt. But the case length differs in 38. It was initially introduced for deeper penetration and higher velocity of rounds. It normally held a total of about 21 grams of black powder. In 1930, Smith and Wesson introduced a modified version of the 38 special with a 5-inch barrel. This was done for police usage purposes.

38 is considered as a low-pressure cartridge in today’s date. This is due to black powder usage in it. The usage of these revolvers is very limited in today’s date. Yet some police personnel still use these for short-barrelled revolvers in some cases. The 38 cartridges are considered adequate for self-defense purposes.

What is 357?

The 357 magnum is a smokeless cartridge. It has a 357 inch bullet diameter and was created and designed by gun manufacturers Smith and Wesson. It originated in the USA in the year 1934. It is still in service since it was produced in 1935. This led to the beginning of the Magnum Era and was renowned for its terminal ballistics. This gun was created responsive to the colts—38 super. The 38 special and 357 have similar and identical properties and parameters. However, the chamberings will seem different.

The 357 cartridge is considered one of the best hunting tools for revolvers. But many prefer the other magnum versions to be more powerful in work. It has less energy than the higher magnum versions, but the diameter is smaller with a high velocity. The bullet choice while the development of the 357 was different. Finally, the final bullet was designed from ideas of both Keith and Sharp bullets.

The 357 magnum can handle pressure up to 300 Mpa. The maximum CUP of 357 is 45,000 CUP. The bullet type differs in design, velocity, and energy. It has an extended case which helps in proper propulsion behind the bullet. Also, the muzzle velocity is quite higher in the case of 357.

The Main Difference Between 38 and 357

  1. The 38 was introduced to provide better velocity and energy than the USA’s previous government-issued guns. But the 357 was introduced to compete with the colt directly. 
  2. Although they have similar diameter part , but the 38 one has a slightly shorter length than 357.
  3. Handguns designed to fire 357 rounds can also fire 38 rounds, but the reverse is not possible. 38 rounds cannot fire 357 rounds every time.
  4. The price of both rounds also differs. The 38 is cheaper as compared to the357.
  5. The differences in velocity, when measured by shooting, remains unnoticeable, but in the case of trajectories, the magnum produces flatter trajectories compared to38. In case of 357 it was found that it has a higher velocity.


Both the cartridge types have a lot of similarities in them though a few differences are also there. The same gun designers and developers have developed both. Both guns could be used for self-defense though recoil, bullet type, etc., must be kept in mind while purchasing these. 

An expert can give much better advice on the cartridge type and what are the important parameters. Yet both the types are good in their respective categories and have a rich legacy and history.


  1. https://www.astm.org/DIGITAL_LIBRARY/JOURNALS/FORENSIC/PAGES/JFS12780J.htm
  2. https://pubs.acs.org/doi/abs/10.1021/ac5004568