Can You Reload .338 Winchester Magnum for Better Performance?

Optimizing Case Capacity

When reloading the .338 Winchester Magnum for moose hunting, consider increasing the case capacity to accommodate heavier bullets. This can be achieved by seating the bullet closer to the case mouth or using a longer case. For example, the Nosler Partition 300-grain bullet requires a minimum case capacity of 84.5 grains of water. To accommodate this, you can use the Winchester Large Rifle case, which has a capacity of 86.4 grains. However, if you opt for the Sierra GameKing 300-grain SP bullet, you’ll need a slightly shorter case, with a capacity of 82.5 grains.

Choosing the Right Powder

Selecting the right powder for your reloaded .338 Winchester Magnum is crucial for achieving optimal performance. For moose hunting, you’ll want a powder that burns slowly and consistently, such as IMR 7828 or H4831. These powders produce a consistent burn rate, which helps maintain accuracy and reduces barrel wear. When loading for a 300-grain bullet, you can start with a charge of 85-90 grains of IMR 7828, and adjust from there to achieve your desired velocity. Keep in mind that using too much powder can lead to excessive recoil and decreased accuracy.

Bullet Selection

When selecting a bullet for your reloaded .338 Winchester Magnum, consider the type of hunting you’ll be doing. For moose, you’ll want a bullet with a high weight retention and a robust construction to withstand high-impact hits. The Nosler Partition 300-grain bullet is a popular choice for moose hunting, offering excellent weight retention and penetration. The Sierra GameKing 300-grain SP bullet is another option, providing a consistent expansion and a high weight retention. Regardless of the bullet you choose, make sure it’s seated correctly in the case, with the ogive (the curved part of the bullet) seated 0.050-0.075 inches into the rifling.