Does a .350 Legend Use a 5.56 Bolt? No, and Here's Why
The short answer is no, a .350 Legend does not use a 5.56 bolt. While both cartridges are used in AR-15 style platforms, their significant design differences necessitate distinct bolt assemblies. Understanding these differences is crucial for firearm safety and proper function.
Cartridge Differences: Size and Pressure
The core reason a .350 Legend bolt won't work in a 5.56 NATO chamber, and vice versa, boils down to fundamental cartridge discrepancies:
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Caliber: The most obvious difference is the caliber. .350 Legend, as its name suggests, has a larger diameter bullet (.350 inches) compared to the 5.56 NATO/.223 Remington's smaller .224-inch bullet. This alone makes them incompatible.
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Case Dimensions: Beyond the bullet, the cartridge cases themselves are substantially different in size and shape. The .350 Legend case is longer and wider, requiring a bolt face designed for those specific dimensions. Attempting to chamber a .350 Legend round in a 5.56 bolt would result in a dangerous and potentially catastrophic malfunction.
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Pressure: While both cartridges operate within the AR-15 platform, the pressure levels generated during firing are different. The .350 Legend operates at higher pressures than the 5.56 NATO. A 5.56 bolt, designed for lower pressures, could be severely damaged or even fail under the stress of a .350 Legend round.
Bolt Face Differences: A Critical Detail
The bolt face is the critical component that directly interacts with the cartridge case during firing. The 5.56 bolt has a smaller bolt face specifically designed for the smaller 5.56 case. A .350 Legend bolt features a larger bolt face appropriately sized to handle the larger cartridge case. The mismatch is not just a matter of a slight size difference; it's a fundamental incompatibility that compromises safety.
AR-15 Platform Variations: Understanding the Nuances
The AR-15 platform is incredibly versatile, and many manufacturers offer upper receivers and lower receivers that are compatible with different calibers. However, simply swapping upper receivers isn't always a straightforward solution. You absolutely must ensure the bolt carrier group (BCG) – which includes the bolt – is specifically designed and rated for the caliber you are using. Mixing and matching components without understanding these crucial differences can lead to serious injury or damage to the firearm.
Safety First: The Importance of Proper Cartridge and Bolt Matching
Using the wrong bolt with any cartridge is extremely dangerous. It is crucial to always verify the correct bolt and BCG are installed for the specific caliber of ammunition being used in your firearm. Consulting your firearm's owner's manual and seeking advice from experienced firearms professionals is highly recommended before attempting any modifications or caliber changes. Improper use can lead to severe injury or death.
