The question, "Can you shoot .308 out of 7.62x51?" is a common one among shooters, and the short answer is generally yes, but with crucial caveats. While the two cartridges look very similar and are often used interchangeably in casual conversation, there are subtle yet significant differences that can lead to safety issues if not carefully considered. Let's delve into the specifics.
Understanding the .308 Winchester and 7.62x51 NATO Cartridges
Both the .308 Winchester and 7.62x51 NATO cartridges fire a .30 caliber bullet, hence the similar naming. However, they are not precisely identical. The key differences lie in:
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Chamber Dimensions: While the bullet diameter is almost the same, the 7.62x51 NATO cartridge has slightly larger chamber dimensions. This means a .308 Winchester round might chamber in a 7.62x51 rifle, but a 7.62x51 round will not chamber in a .308 Winchester rifle.
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Case Head Dimensions: The case head, the base of the cartridge case, is slightly larger in the 7.62x51 NATO. This difference is critical for safety. A .308 Winchester round fired in a 7.62x51 chamber might experience higher pressures, potentially leading to catastrophic failure of the rifle.
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Powder Charges: 7.62x51 NATO rounds generally have higher powder charges than .308 Winchester rounds. This further contributes to the higher pressure potential when firing .308 in a 7.62x51 chamber.
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Headspace: Headspace is the distance between the bolt face and the cartridge case head. Variations in headspace between rifles chambered for these cartridges can exacerbate the pressure issues.
The Risks of Mixing Cartridges
Firing a .308 Winchester round in a rifle chambered for 7.62x51 NATO is not without significant risk. The potential consequences include:
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Increased Pressure: The larger chamber can cause the .308 round to experience higher pressure than it was designed for, leading to:
- Bullet deformation: The bullet might deform before leaving the barrel, affecting accuracy and potentially causing dangerous ricochets.
- Case rupture: The cartridge case could rupture, causing serious injury to the shooter.
- Barrel damage: Over time, repeatedly firing .308 in a 7.62x51 chamber can lead to damage and wear to the barrel, decreasing its lifespan and accuracy.
- Receiver damage: The increased pressure can damage the rifle's receiver, rendering it unsafe to use.
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Unreliable Function: In some cases, the slightly smaller dimensions of the .308 Winchester round can lead to unreliable feeding and extraction.
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Potential for Misfire: Although less common, the case head difference can lead to problems with primer ignition.
When It Might Seem Safe (But Isn't!)
Some manufacturers produce rifles that claim to handle both .308 and 7.62x51 NATO. However, even in these cases, it's crucial to check the manufacturer's specifications and recommendations carefully. They may stipulate using only certain types of ammunition or state limitations on usage. Assuming compatibility without confirmation is incredibly risky.
Case Study: A Near-Miss
While finding documented cases of catastrophic failure from mixing these cartridges is difficult due to liability reasons, anecdotal accounts exist where shooters experienced increased pressure signs, including bulging cases or excessive recoil. Such incidents underline the importance of adhering to manufacturer specifications.
The Bottom Line: Safety First!
While there might be temptation to use readily available .308 ammunition in a 7.62x51 rifle, it's strongly discouraged. The potential for serious injury or even death is far too high to take the risk. Always use the ammunition specifically recommended by the rifle's manufacturer. If you are unsure, consult a qualified firearms expert.
Frequently Asked Questions (FAQs)
Q: Can I visually distinguish between .308 Winchester and 7.62x51 NATO rounds?
A: No. The visual differences are subtle and require careful examination. Relying on visual identification is unsafe.
Q: My rifle is marked as "multi-caliber." Can I shoot both?
A: Check the manufacturer's specifications. Even multi-caliber rifles often have restrictions or recommendations concerning specific ammunition types.
Q: What if I accidentally load a .308 round into my 7.62x51 rifle?
A: Do not fire the weapon! Carefully unload the rifle and check it for any damage.
By understanding the subtle yet crucial differences between .308 Winchester and 7.62x51 NATO cartridges, shooters can prioritize safety and avoid potentially hazardous situations. Remember, firearm safety should always be the top priority.