Nowadays a lot of attention is given to controlled expansion bullets that are stuffed full of lots of advanced technology. Monolithic, bonded, and tipped bullets are incredibly popular. However, standard cup and core bullets are still just as effective as they have always been. Today we take a look at a top quality cup and core bullet in the Sierra Gameking.
Background
Sierra bullets has been making bullets for over 70 years. For a long time the 175 grain Sierra Matchking in a 308 was the load for tactical precision matches. Sierra makes cup and core bullets both for target shooting as well as hunting. Currently, their hunting line features the Sierra Gamechanger, the succesor to the Sierra Gameking. The Gameking provides a high-end bullet while managing to remain less expensive than premium controlled expansion competitors like Barnes TTSX and Federal’s Terminal Ascent bullets.
Cup and core bullets tend to expand very rapidly and transfer energy quickly. This can oftentimes result in spectacular visible effect on game. The downside to rapid expansion is that rapid expanding bullets are often prone to breaking apart. This is more likely to happen if impact velocities are especially high or large masses of bone such as the shoulder are encountered. If this does happen the smaller fragments of bullet don’t penetrate as well as a bullet that stays in one piece. This phenomenon is called core-jacket separation. For a more in depth look at the different classes of bullets check out the article on how to pick a bullet.
Design and External Ballistics
The Sierra Gameking is a cup and core bullet with an exposed lead tip. There are versions both with and without a boat tail. BC’s are middle of the pack, matching up similarly to the Nosler Accubond family of bullets. Most standard weight Gameking bullet’s will have G1 BC’s between 0.400 and 0.500.
In my experience, I have found Sierra Gamekings to be an exceptionally accurate bullet. I have shot the Gamekings through a variety of rifles and have found it easy to work up a load, especially compared to other bullets. My Ruger American, Tikka T3X, and Husqvarna 1640 all shot the Gamekings into sub minute of angle with little to no load development. In the case of my Husqvarna, the load I tested had actually been developed for the Ruger American.
Terminal Performance
The terminal performance of the Gamekings has been strong, with a few qualifiers. There have been strong blood trails and quick deaths from moderately sized animals shot with the Sierra. The bullet exited about half the time. In other cases the bullet came to rest against the offside hide.
However, the good terminal performance needs to take into account the context. The recovered bullets retained about 60 percent of their original weight. They shed this weight despite the fact that they had relatively low impact velocities. My hunting load with the Gamekings only pushes them at a conservative 2650fps at the muzzle. This indicates that the Gamekings are a soft bullet and may have poor weight retention and penetration if driven fast.
Closing Thoughts
First of all, the terminal performance of the Sierra Gameking proves that it is an effective hunting bullet. That said, the Gameking is a poor choice for an all around western hunting load due to its lower weight retention and good but not great penetration. The outstanding accuracy of the bullet does make up for its softer composition in certain scenarios.
With this in mind, I recommend the Gameking for shooting thinner skinned game such as deer, black bear, and antelope. It is advisable to avoid the Gameking for use in magnum cartridges. This is because the excessive velocity risks to expand the bullet to rapidly at the cost of penetration.
In conclusion, the optimal use case for the Gamekings is hunting thin skinned game with a conventional cartridge with modest velocities. The soft Gameking will expand and transfer energy well even at lower velocities, and the accuracy helps to put the bullet right where you aim it. Standard velocities minimize the potential for excessive fragmentation and jacket core separation. For deer hunting with cartridges like the 308 Winchester, the 7-08 Remington, and the 6.5 Creedmoor the Sierra is an excellent choice.