Does Bullet Seating Depth Change with Powder Type?

Powder Type and Case Capacity

When using different types of powders, the optimal bullet seating depth may change due to variations in case capacity and pressure curves. For example, a fast-burning powder like IMR 4350 may require a slightly deeper seating depth than a slower burning powder like H1000.

Considerations for Different Powder Types

To determine the optimal bullet seating depth for your specific powder type, consider the following factors: the powder’s burn rate, case capacity, and the desired pressure level. A good starting point is to use a ballistic calculator or consult the manufacturer’s recommendations for maximum overall length (MOL) and recommended seating depth. For instance, when using a fast-burning powder, a shallower seating depth may be required to prevent over-pressure, while a slower burning powder may allow for a deeper seating depth.

Benchrest and Hunting Load Considerations

In benchrest shooting, where precision is paramount, a shallower seating depth may be preferred to minimize bullet jump and ensure consistent accuracy. However, in hunting loads, where expansion and penetration are critical, a deeper seating depth may be necessary to achieve optimal performance. In such cases, the powder type and case capacity must be carefully selected to ensure the desired pressure level and bullet expansion.