Quick Answer
Inconsistent accuracy with 7mm SAUM reloads can be caused by variable powder charge, insufficient case preparation, or improperly seated bullets. Check your loading data and procedures to ensure consistency. Consider using a precision loading die set and a digital scale for accurate measurements.
Insufficient Case Preparation
For 7mm SAUM cases, ensure the cases are properly resized and chamfered, with a deburring tool used to remove any sharp edges. A case trim length of 1.855 inches is recommended. This helps prevent case headspace issues and ensures consistent chambering. Use a precision case gauge to verify headspace.
Precision Loading and Measuring
Use a high-precision digital scale, such as the A&D FX-1600i, to weigh charges to the recommended 85-90 grains of H1000 or Varget powder. A loading die set like the Redding T-7 or Lee Classic Turret is ideal for precise seating and crimping of bullets. Load a minimum of 20 rounds to establish a baseline for accuracy testing.
Bullet Seating and Crimping
For 7mm SAUM, it’s essential to seat the 140-grain or 150-grain bullets at 0.050-0.060 inches off the lands, using a precise seating die. This helps prevent bullet shift during firing, which can cause accuracy issues. Use a crimping die to apply a consistent crimp, as excessive crimping can lead to inconsistent expansion and accuracy problems.
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