Will a .308 Shoot 7.62x51? Understanding Cartridge Compatibility
The short answer is: generally, yes, but with important caveats. The .308 Winchester (7.62x51 NATO) and 7.62x51 NATO cartridges are very similar, leading to frequent confusion. However, subtle differences exist that can affect firearm functionality and safety.
Let's break down the nuances:
The Similarities: Why the Confusion Exists
Both the .308 Winchester and 7.62x51 NATO cartridges fire a .308 caliber bullet and have very similar dimensions. This leads many to believe they're interchangeable. The bullet diameter is practically identical, and the case length is close enough that many rifles chambered for one will seemingly accept the other.
The Key Differences: Why Interchangeability is Risky
While seemingly minor, these differences can lead to dangerous consequences:
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Chamber Dimensions: The 7.62x51 NATO chamber is slightly larger than the .308 Winchester chamber. This means a .308 round fired from a 7.62x51 NATO chamber will generally function correctly, albeit potentially with slightly increased pressures. However, a 7.62x51 NATO round fired from a .308 Winchester chamber is a different story. The larger case of the 7.62x51 NATO can lead to overpressure, a dangerous situation that can result in catastrophic firearm failure, including barrel rupture, receiver damage, and serious injury or death.
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Case Head Dimensions: Although often overlooked, subtle differences in the case head dimensions can also cause issues. The 7.62x51 NATO round has a slightly stronger case head than the .308 Winchester round.
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Maximum Average Pressure (MAP): While the bullet diameters are similar, the maximum average pressure (MAP) allowed for each round differs. The 7.62x51 NATO has a higher MAP, meaning it generates higher pressure upon firing. Firing this higher-pressure round in a .308 Winchester chamber can lead to overpressure and catastrophic failure.
The Bottom Line: Safety First
While many rifles chambered in 7.62x51 NATO may accept .308 Winchester rounds, it's strongly discouraged to fire 7.62x51 NATO rounds in a rifle chambered for .308 Winchester. The risk of catastrophic firearm failure is too great.
Always consult your firearm's owner's manual for explicit information on compatible ammunition. Never assume compatibility based on visual similarities alone.
Manufacturer Recommendations: The Ultimate Authority
Ultimately, the manufacturer's specifications for your specific firearm are the definitive guide. If the manual doesn't explicitly state compatibility, do not attempt to fire a different cartridge. Safety should always be the top priority when handling firearms.
