The question "What caliber is a 20 gauge slug?" reveals a common misconception about shotguns and their ammunition. The answer isn't a simple caliber designation like .308 or 9mm. Instead, it's crucial to understand the difference between gauge and caliber.
Gauge vs. Caliber: A Key Distinction
Gauge, in the context of shotguns, refers to the bore diameter. It's determined by the number of lead balls, each with a diameter equal to the bore, that it takes to weigh one pound. A 20 gauge shotgun, therefore, means it takes 20 lead balls to equal one pound. The smaller the gauge number, the larger the bore diameter.
Caliber, on the other hand, typically refers to the diameter of a bullet in either inches or millimeters (e.g., .308 Winchester, 9mm). This system applies primarily to rifles and handguns, not shotguns.
Understanding 20 Gauge Slugs
While a 20 gauge slug doesn't have a caliber in the traditional sense, its diameter can be measured. The diameter of a 20 gauge slug varies slightly depending on the manufacturer and the specific type of slug (rifled slugs tend to be slightly larger than foster slugs), but it generally falls within the range of .618 inches to .62 inches. This is often approximated as .62 caliber. However, it's essential to remember that this is a measurement derived from the gauge, not a standardized caliber designation like those used for rifles and handguns.
Types of 20 Gauge Slugs
Different types of 20 gauge slugs offer varying performance characteristics:
1. Foster Slugs:
- These are relatively inexpensive and are often chosen for their simplicity.
- They are typically round and have a relatively wide spread at longer ranges.
2. Rifled Slugs:
- Designed to be fired from barrels with rifling, these slugs exhibit greater accuracy and range due to the spin imparted by the rifling.
- They are more expensive than Foster slugs.
3. Sabot Slugs:
- These slugs use a plastic or other material sabot to reduce friction and improve accuracy.
- They often deliver higher velocities than other slug types.
Choosing the Right 20 Gauge Slug
Selecting the right 20 gauge slug depends on the intended application. For hunting at longer ranges, a rifled slug or a sabot slug is generally preferred. For close-range applications or situations where a wider spread is desired, a Foster slug might be a suitable choice. Always check the manufacturer's specifications and your firearm's manual to ensure compatibility.
Conclusion
A 20 gauge slug doesn't have a caliber in the same way that rifle or handgun ammunition does. Its diameter is roughly .62 inches, a measurement derived from the 20 gauge designation. Understanding the distinction between gauge and caliber is critical for safely and effectively using shotgun ammunition. Remember to always choose the appropriate slug type for your intended use and ensure compatibility with your shotgun.
