The Hornady 7mm-08 139 gr SST is a popular choice among hunters and target shooters for its impressive accuracy and consistent performance. This detailed analysis explores the ballistics of this specific cartridge, its practical applications, and factors influencing its trajectory. We'll delve beyond simple ballistic charts to provide a comprehensive understanding of this versatile round.
Understanding the 7mm-08 Remington Cartridge
Before we dive into the specifics of the 139 gr SST, it's important to understand the 7mm-08 Remington itself. This cartridge, a bottlenecked design, offers a great balance between power and recoil, making it suitable for a wide range of game. Its relatively mild recoil allows for comfortable shooting, even for newer shooters, while still delivering sufficient energy for medium to large game animals within its effective range. Its popularity stems from its versatility and adaptability, finding use in everything from varmint hunting to taking down larger game such as deer and antelope.
Hornady 139 gr SST: Bullet Construction and Performance
The Hornady 139 gr SST (Super Shock Tip) bullet is a bonded, polymer-tipped projectile designed for superior accuracy and controlled expansion. The bonded core ensures consistent weight retention even upon impact, leading to deeper penetration. The polymer tip promotes rapid expansion, generating a devastating wound channel. This combination makes it exceptionally effective on game animals.
Key Ballistic Characteristics (Approximate):
These values are approximate and can vary based on factors such as barrel length, twist rate, and atmospheric conditions. Always refer to your specific firearm and ammunition data for the most accurate information.
- Muzzle Velocity: Around 2600-2700 fps (feet per second) from a 22-inch barrel.
- Muzzle Energy: Roughly 2,500-2,700 ft-lbs (foot-pounds) of energy.
- Trajectory: Relatively flat trajectory for its caliber, allowing for accurate shots at extended ranges.
- Effective Range: Generally considered effective up to 300-400 yards on game animals, depending on the shooter's skill and environmental conditions.
Factors Affecting Ballistics
Several factors significantly influence the actual ballistic performance of the Hornady 7mm-08 139 gr SST:
1. Barrel Length:
Longer barrels generally produce higher muzzle velocities and increased energy. Shorter barrels will result in a lower muzzle velocity and energy.
2. Barrel Twist Rate:
The twist rate of your rifle barrel is crucial for bullet stability. An improper twist rate can lead to inaccurate shots and poor bullet performance.
3. Atmospheric Conditions:
Temperature, humidity, and altitude all affect the ballistic trajectory. Higher altitudes and lower temperatures will result in slightly higher velocities, while humidity tends to slow down bullets.
4. Ammunition Variations:
Even within the same lot of ammunition, slight variations in manufacturing can impact muzzle velocity and accuracy.
Practical Applications
The Hornady 7mm-08 139 gr SST finds application in a variety of hunting scenarios:
- Deer Hunting: An excellent choice for deer hunting, offering sufficient stopping power and penetration.
- Antelope Hunting: Its flatter trajectory makes it suitable for antelope hunting, allowing for accurate shots at longer ranges.
- Predator Hunting (larger predators): While not ideal for smaller varmints, it can effectively handle larger predators like coyotes or bobcats.
Conclusion:
The Hornady 7mm-08 139 gr SST is a highly effective cartridge well-suited to various hunting applications. Understanding the factors impacting its ballistics is crucial for maximizing its performance and achieving accurate, ethical shots. Always consult ballistics charts and data relevant to your specific rifle and environmental conditions to ensure safe and successful hunts. Remember to prioritize safety and ethical hunting practices.
