7.62 NATO vs. .308 WIN:

A Detailed Comparison

Two popular cartridges that often cause confusion among shooters are the 7.62 NATO and .308 WIN. At first glance, they appear nearly identical, but subtle variations can significantly impact performance. Let’s examine the similarities and differences between 7.62 NATO and .308 WIN ammunition.

Origins and Nomenclature

7.62 NATO and .308 WIN are closely related, but their origins and nomenclature are the first key distinctions to consider:

7.62 NATO

• Developed in the 1950s for military use
• The official military designation, also known as 7.62x51mm
• Designed for use in military rifles like the M14 and M60

.308 WIN

• Developed for civilian and sporting purposes
• Civilian designation, also known as .308 Winchester
• Designed for commercial rifles and hunting

Pressure Levels

One of the most significant differences between 7.62 NATO and .308 WIN is the chamber pressure they generate:

7.62 NATO

• Loaded to a slightly lower pressure level than .308 WIN
• Designed for military rifles that require reliable cycling under sustained firing

.308 WIN

• Loaded to higher pressure levels, typically around 62,000 PSI
• Designed for commercial rifles built to SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) specifications

Chamber Dimensions

The chamber dimensions for these cartridges also differ slightly:

7.62 NATO

• Generally has a longer chamber throat
• Accommodates a longer cartridge length, which can affect bullet seating
  

.308 WIN

• Typically has a shorter chamber throat
• Designed for shorter cartridge lengths, which can improve accuracy.

Interchangeability

While the cartridges can be similar, it's important to note that they are not always interchangeable due to the factors mentioned above. However, there are some guidelines to follow:

• 7.62 NATO ammunition can generally be safely fired in a .308 WIN chambered rifle. This is because 7.62 NATO is typically loaded to lower pressures, and .308 WIN rifles are built to withstand higher pressures.
• Firing .308 WIN ammunition in a 7.62 NATO chambered rifle is generally not recommended. The higher pressure of .308 WIN ammunition may exceed what a 7.62 NATO rifle can safely handle.

Performance and Ballistics

Both 7.62 NATO and .308 WIN are versatile cartridges suitable for various applications, but there can be some differences in their performance:

• 7.62 NATO: It is often used in military applications and is known for its reliability and durability. It may be less consistent in terms of accuracy compared to .308 WIN due to the longer chamber throat.
• .308 WIN: It is favored by civilian and sporting shooters and is renowned for its accuracy. The shorter chamber throat can lead to improved precision.

Availability and Cost

7.62 NATO ammunition can sometimes be less expensive due to its military surplus availability. .308 WIN ammunition is more commonly found in sporting goods stores and can vary in price based on brand and bullet type.

While 7.62 NATO and .308 WIN ammunition may appear similar, there are notable differences in their origins, pressure levels, chamber dimensions, and performance. Understanding these distinctions is essential for making informed decisions when selecting the proper ammunition for your firearm. Always adhere to the manufacturer's recommendations for your rifle and cartridge, and remember that safety should be the top priority in any shooting activity.