What is Atlas Ballistics?

Atlas Ballistics manages 2 data types including support articles. Helps you organize, track, and share your work in 1 place for teams and solo users.

What is maximum point-blank range (MPBR)?

MPBR is the farthest distance a predicted trajectory remains inside a chosen vertical target zone while aiming at its center without an elevation correction. It depends on velocity, ballistic coefficient, sight height, atmosphere and the zone diameter. It is not a guarantee of a hit or a maximum ethical hunting distance.

How does the optimal-zero calculator work?

The calculator adjusts the departure angle in the Atlas trajectory engine until the peak is just below half the target-zone diameter above your line of sight. It then finds the near zero, far zero and distance where the bullet falls below the lower boundary. The far zero is the suggested zero distance. Results are interpolated numerical estimates for a level shot in still air.

Is target-zone diameter the same as radius?

No. A 6-inch diameter permits up to 3 inches above and 3 inches below the point of aim. Group size, zero error, wind and range uncertainty also use up that allowance. Choose a smaller zone if you need a margin; the calculator does not model shot dispersion.

What if my sight height exceeds the target-zone radius?

The bullet starts below the lower boundary. The result shows the distance where it first enters the zone, rather than claiming it is inside the zone from the muzzle.

Can I sight in at 100 yards instead?

The result includes the predicted point of impact at 100 yards for the optimized zero. Treat it as a starting point: confirm the actual far zero and downrange impacts with your rifle, ammunition and conditions. Rounding a zero distance can slightly change the trajectory.

Features

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Free ballistic tool

MPBR & Optimal Zero Calculator

Find the zero that keeps your predicted trajectory inside a chosen target zone—then verify it at the range.

Choose a load and target zone

Finding the zero that fits your target zone…

How to use your optimal zero

Start with a load example, then enter your measured muzzle velocity and the matching G1 or G7 coefficient. Measure sight height from the bore center to the optic center. Enter the full target-zone diameter, not its radius.

The suggested far zero places the top of the trajectory just inside the upper boundary. The near zero is its first crossing of your line of sight; MPBR is where it falls through the lower boundary. The 100-yard impact provides a starting point for sighting in at a shorter range.

This is a vertical trajectory envelope for level, still-air conditions, not a model of the entire shot group. Leave room for dispersion and uncertainty. Wind and terminal performance must be assessed separately; MPBR alone does not establish a suitable hunting distance.

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