Quick Answer
To manually adjust your data card for altitude changes, locate the elevation adjustment column on your data card, then reference the elevation correction table to determine the correction value for your current altitude. This correction value is usually expressed in inches of bullet drop. Adjust the elevation dial on your scope or reticle to match the corrected value.
Understanding Altitude Adjustment
When hunting at high elevations, a lower air density can affect bullet flight, resulting in less drag and a flatter trajectory. Conversely, at sea level, a higher air density increases drag, causing bullets to drop more rapidly. To compensate for these changes, you’ll need to adjust your rifle’s point of aim to match the local altitude.
Reference Data Card
Consult your ballistics data card to determine the elevation correction for your specific rifle and cartridge. These corrections are usually expressed in inches of bullet drop for a given elevation. For example, if your rifle experiences 12 inches of bullet drop at 1000 feet elevation, but you’re hunting at 5000 feet, you’ll need to add 12 inches to the correction value to account for the change in density. This would result in a total elevation correction of 24 inches.
Practical Application
To apply this correction, locate the elevation adjustment column on your data card, which is usually a chart or table showing the correction values for various elevations. Reference this chart to determine the correction value for your current location. Then, adjust the elevation dial on your scope or reticle to match the corrected value. For example, if your scope has an elevation dial with 20 MOA (minute of angle) clicks, and your data card indicates a 24-inch correction, you would adjust the dial to 12 MOA, as 1 MOA equals 1 inch at 100 yards.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.