Can 7.62x51mm Shoot .308 Winchester? The Complex Answer
The short answer is: generally no, but it depends. While both 7.62x51mm NATO and .308 Winchester cartridges look very similar and share the same basic projectile diameter (.308 inches), they are not interchangeable. Attempting to fire a .308 Winchester round in a 7.62x51mm NATO chamber can be dangerous. Let's delve into the specifics.
Understanding the Differences: More Than Just a Name
The confusion stems from the similar naming conventions and near-identical bullet diameters. However, crucial differences exist in cartridge dimensions:
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Case Length and Dimensions: The 7.62x51mm NATO cartridge case is slightly longer than the .308 Winchester case. This seemingly small difference can lead to significant problems. The longer NATO case can cause excessive pressure in a .308 Winchester chamber, leading to catastrophic weapon malfunction or injury.
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Chamber Specifications: The chambers themselves are designed with differing tolerances to accommodate these dimensional variations. A 7.62x51mm chamber is designed to handle the higher pressures generated by the longer NATO cartridge. A .308 Winchester chamber is not.
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Pressure Differences: 7.62x51mm NATO cartridges operate at higher pressure than .308 Winchester rounds. Firing a 7.62x51mm round in a .308 Winchester chamber is generally safe (though not recommended without professional guidance and understanding the risks), but the reverse is significantly more dangerous.
The Risks of Using Incorrect Ammunition
Attempting to fire the wrong cartridge can result in:
- Overpressure: The most serious risk. This can lead to a ruptured case, damaging the firearm, causing serious injury to the shooter, or even death.
- Stuck Cases: The longer 7.62x51mm case may become jammed in the .308 Winchester chamber, requiring significant effort to remove.
- Damage to the Firearm: The increased pressure can cause damage to the barrel, bolt, or other parts of the firearm, rendering it unusable.
When it Might Seem Possible (Proceed with Extreme Caution!)
Some older .308 Winchester rifles might have chambers that are slightly oversized, offering a greater degree of compatibility. However, this is not a guarantee, and it remains incredibly risky. Never assume compatibility without a thorough inspection by a qualified gunsmith.
The Bottom Line: Safety First
While the bullet diameters are almost identical, attempting to mix and match 7.62x51mm and .308 Winchester ammunition is highly dangerous and should never be done. Always double-check your ammunition before loading and firing any firearm. If you are unsure about the compatibility of your ammunition and firearm, consult a qualified gunsmith or experienced firearms professional. Your safety is paramount.
