The question, "Can you shoot 7.62 x 51 in .308?" is a common one among shooters, and the short answer is generally no, but with caveats. While both cartridges look similar and share the same basic diameter (.308 inch), there are critical dimensional differences that can lead to serious consequences if you try to force a 7.62 x 51 mm NATO round into a .308 Winchester chamber. This article delves deep into the specifics, explaining the risks and potential outcomes.
Understanding the Cartridge Differences: 7.62 x 51 vs .308 Winchester
The confusion stems from the near-identical bullet diameter. However, the key difference lies in the case dimensions. 7.62 x 51 mm NATO rounds have a slightly larger case diameter and overall length. This seemingly small difference can have significant implications:
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Case Head Diameter: The 7.62 x 51 mm case head is larger, meaning it won't fit into a .308 Winchester chamber. Forcing it could cause damage to the firearm.
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Case Length: The 7.62 x 51 mm case is longer, which can lead to overpressure within the .308 chamber. This is extremely dangerous.
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Web Thickness: The web (the thinnest part of the case) is thicker on the 7.62 x 51 mm cartridge, adding to the pressure issues.
| Feature | 7.62 x 51 mm NATO | .308 Winchester |
|---|---|---|
| Bullet Diameter | .308 inch | .308 inch |
| Case Length | 2.012 inches | 1.963 inches |
| Case Head Diameter | Larger | Smaller |
| Web Thickness | Thicker | Thinner |
| Pressure | Higher (typically) | Lower (typically) |
The Dangers of Mixing 7.62 x 51 and .308 Winchester
Attempting to fire a 7.62 x 51 mm round in a .308 Winchester rifle can result in several dangerous situations:
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Chamber Rupture: The most severe outcome. The excessive pressure generated by the larger 7.62 x 51 mm case in the smaller .308 chamber can cause the chamber to fail, resulting in significant damage to the firearm and potential injury to the shooter.
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Barrel Damage: Even if the chamber doesn't rupture, the increased pressure can damage the barrel, rendering the rifle unusable.
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Bolt Failure: The increased pressure can also cause the bolt to fail, leading to injuries.
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Catastrophic Failure: In extreme cases, the entire firearm can experience catastrophic failure, with potentially devastating consequences.
Case Study: There have been numerous documented instances where forcing a 7.62 x 51 mm round into a .308 chamber has resulted in significant firearm damage. These incidents highlight the risks associated with ignoring the dimensional differences.
What About Rifles Marked as ".308/.7.62"?
Some rifles are explicitly marked as being compatible with both .308 Winchester and 7.62 x 51 mm NATO rounds. These rifles have chambers specifically designed to handle both cartridges safely. However, it is crucial to verify the manufacturer's specifications before using either cartridge in such a rifle.
Safe Practices: Always Double-Check Your Ammunition
The most critical step to preventing accidents is verifying the ammunition before loading it into your firearm. Never assume that a round will fit; always visually check the markings on the cartridge to confirm it matches the specifications of your rifle.
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Visual Inspection: Check the cartridge case markings to ensure it's the correct caliber.
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Ammunition Storage: Store your ammunition appropriately and separately to prevent accidental mixing.
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Regular Maintenance: Regularly inspect your firearm for any damage or wear.
Conclusion: Avoid the Risk
While the temptation to use readily available ammunition might be strong, it's crucial to prioritize safety. Never attempt to fire a 7.62 x 51 mm round in a rifle chambered for .308 Winchester. The potential consequences are far too severe. Always follow safe firearm handling practices and adhere to the manufacturer's specifications for your specific rifle. The difference might seem insignificant, but it can be deadly.