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Can You Shoot 22 Magnum in a 22LR (and Vice Versa)?

.22 ammunition and an automatic gun on black background

For firearm enthusiasts and newcomers alike, the compatibility of .22 Magnum and .22 LR cartridges is a common question. With many people curious about the interchangeability of these two types of ammunition, it’s crucial to address the matter and ensure safety in firearm usage.

You cannot shoot a .22 Magnum in a .22 LR, and vice versa. Attempting to do so can be dangerous and may cause damage to your firearm. The differences in case size, bullet diameter, and pressure between these cartridges make them incompatible.

I’ve been using the .22 WMR for squirrel hunting for nearly 20 years, and while I also see the .22 Magnum’s value for short-range hunting or pest control, it’s always been clear to me that these cartridges are not the same. In this article, I’ll examine the differences between the .22 Magnum and .22 LR cartridges so you can make informed decisions and stay safe.

The Dangers of Shooting .22 Magnum in a .22 LR (and Vice Versa)

Attempting to shoot a .22 Magnum cartridge in a firearm chambered for .22 LR, or vice versa, can be dangerous for you and the firearm. Here are some potential dangers and consequences of interchanging these two types of ammunition:

  • Chamber pressure: Shooting a .22 Magnum cartridge in a .22 LR chamber can cause excessive pressure, which could result in a catastrophic failure of the firearm. This could injure you and/or damage the firearm beyond repair.
  • Inaccuracy and inconsistency: If you fire a .22 LR cartridge in a .22 Magnum chamber, the bullet may not properly engage the rifling, which can lower accuracy and make shooting ineffective and unsafe.
  • Damage to the firearm: If you use .22 Magnum or .22 LR cartridges in a firearm not designed for either type of ammunition, you may damage the chamber, barrel, and other components. At best, this could reduce the accuracy and consistency of the firearm. At worst, it could prevent it from working altogether.
  • Legal consequences: In some jurisdictions, modifying a firearm to accept a different type of ammunition than it was designed for, or using ammunition not intended for the firearm, can be illegal and result in legal consequences for the owner.

The Differences Between .22 Magnum and .22 LR Cartridges

Winchester 22 LR Ammo Box

The .22 Magnum, also known as the .22 Winchester Magnum Rimfire (.22 WMR), and the .22 Long Rifle (.22 LR) are both rimfire cartridges, but they have distinct differences that make them incompatible with one another:

  • Case dimensions: The .22 Magnum cartridge is larger than the .22 LR. The case of the .22 WMR is approximately 1.06″ (26.8 mm) long, but the .22 LR case measures about 0.61″ (15.49 mm).
  • Bullet diameter: The bullet diameter of the .22 Magnum is slightly larger than that of the .22 LR. The .22 WMR has a bullet diameter of about 0.224″ (5.59mm), but the 22LR bullet diameter is roughly 0.223″ (5.59mm). This difference may seem small, but it is significant regarding the fit and function of the ammunition in the firearm.
  • Bullet weight and velocity: The .22 Magnum is typically a heavier bullet with a higher velocity than the .22 LR. This means the .22 WMR has more energy and a flatter trajectory. I always have much better results at the range with the .22 WMR, so I prefer it for hunting squirrels, especially since the range tends to be longer.

Final Thoughts

Shooting a .22 Magnum in a .22 LR, or vice versa, is unsafe, ineffective, and not recommended. The differences in case size, bullet diameter, and pressure between these cartridges make them incompatible. Attempting to interchange them can lead to dangerous situations, damage to your firearm, and possible legal consequences.

For more, don’t miss Can You Shoot 2 3/4″ Shells in a 3″ Chamber? | What to Know.