Quick Answer
Slope has a significant impact on rifle zeroing, causing variations in point of impact due to the change in trajectory. This effect becomes more pronounced at longer ranges and with more extreme angles. Proper adjustment for slope is necessary to ensure accurate shots.
Understanding Slope and Trajectory
When shooting uphill or downhill, the bullet’s trajectory is affected by the angle of the slope. The bullet will drop more rapidly on the uphill shot and less rapidly on the downhill shot. This effect is due to the increased or decreased air resistance, respectively. For example, at a 30-degree uphill angle, the bullet will drop approximately 10-15 inches more than at the same range on level ground. Conversely, at a 30-degree downhill angle, the bullet will drop approximately 10-15 inches less.
Slope and Rifle Zeroing
To account for the slope, you must adjust your rifle’s zero. This can be done using a ballistics calculator or by observing the effects of the slope on your shots. For uphill shots, increase your zero by the calculated amount to compensate for the increased drop. For downhill shots, decrease your zero by the calculated amount to compensate for the reduced drop. It’s essential to note that the amount of adjustment required will vary depending on the range, angle, and ballistic coefficient of the bullet. A general rule of thumb is to adjust the zero by 1-2 MOA (minutes of angle) for every 10 degrees of slope.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.