Quick Answer
For precision tuning your rifle, the best ammo types to consider are match-grade, high-ballistic-coefficient (BBC) cartridges with a flat, consistent powder burn. Look for loads with a high standard deviation of velocity (SDV) and a low extreme spread (ES). This will help you achieve consistent group sizes and minimize wind deflection.
Choosing the Right Cartridge
When selecting a cartridge for precision tuning, consider those with a high ballistic coefficient (BC). A BC of 0.5 or higher is ideal for long-range shooting. Examples of high-BC cartridges include the .308 Winchester with a 168-grain MatchKing bullet (BC: 0.6) and the .300 Winchester Magnum with a 190-grain Berger VLD (BC: 0.7). These cartridges will maintain their trajectory and resist wind deflection better than lower-BC options.
Understanding Ballistic Performance
To evaluate the ballistic performance of your chosen cartridge, consult the manufacturer’s data sheet or use a ballistic calculator. Look for the standard deviation of velocity (SDV) and extreme spread (ES) of the load. A lower SDV (less than 20 fps) and ES (less than 50 fps) indicate a more consistent burn and less wind deflection. For example, a .308 Winchester load with a SDV of 15 fps and ES of 30 fps will exhibit better long-range accuracy than a load with a SDV of 30 fps and ES of 60 fps.
Loading and Tuning Techniques
To achieve optimal precision, consider the following loading and tuning techniques: use a consistent powder charge, carefully adjust the seating depth of the bullet, and ensure proper chamber and barrel alignment. Additionally, experiment with different barrel lengths to find the optimal length for your cartridge. For example, a .308 Winchester may exhibit better accuracy with a 22-inch barrel, while a .300 Winchester Magnum may perform better with a 24-inch barrel.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.