How do seating depth adjustments impact 7mm SAUM loads?

Understanding the Relationship Between Seating Depth and Load

When it comes to 7mm SAUM loads for elk hunting, seating depth is a critical factor in determining the overall performance of the cartridge. A deeper seating can lead to increased expansion and a more controlled penetration, which is beneficial for larger game like elk. However, this can also result in a loss of kinetic energy due to the increased bullet weight and the added friction at the case mouth.

Seating Depth and Bullet Design

The seating depth also affects the bullet’s aerodynamics and terminal performance. In general, a shallower seating is more suitable for lighter bullets with a longer ogive, while a deeper seating is better suited for heavier bullets with a shorter ogive. For example, a bullet like the Berger 120-grain VLD, which has a long ogive and is typically seated at 2.80 inches to 2.90 inches in a 7mm SAUM, may benefit from a shallower seating to achieve optimal performance. On the other hand, a bullet like the Hornady 150-grain ELD-X, which has a shorter ogive and is typically seated at 2.90 inches to 3.00 inches, may require a deeper seating to achieve the desired expansion and penetration.

Practical Considerations for Seating Depth

In practical terms, the optimal seating depth for 7mm SAUM loads will depend on the specific bullet design, the desired level of expansion and penetration, and the intended use of the cartridge. As a general rule, a seating depth of 2.80 inches to 3.00 inches will provide a good balance between expansion and penetration for most applications. However, this can be adjusted based on the specific requirements of the hunt and the preferences of the shooter.