Range, bullet drop, and angle calculator for use with telescopic gun sights

An apparatus, useable with a telescopic sight having a mildot reticle, for determining the distance to a target of a known dimension, the apparatus comprising:

• a first rule member;
• a second rule member controllably moveable adjacent to said first rule member;
• a mildot scale, comprising mil value marks, on said first rule member;
• a range scale, comprising range value marks, on said first rule member;
• an index point on said second rule member proximate to said range scale;
• a target dimension scale, comprising dimension value marks, on said second rule member adjacent to said mildot scale;
• and
• said second rule member controllably movable to align a dimension value mark corresponding to the known dimension with a selected mil value mark on said mildot scale, thereby aligning said index point with a range value mark corresponding to the distance to the target.

An apparatus, useable with a firearm having a telescopic sight including a mildot reticle and having a known bullet drop or drift over a known distance, for determining the distance to a target of a known dimension and for determining an adjustment to firearm elevation or windage to compensate for bullet drop or drift, said apparatus comprising:

• a first rule member;
• a second rule member controllably moveable adjacent to said first rule member;
• a mildot scale, comprising mil value marks, on said first rule member;
• a range scale, comprising range value marks, on said second rule member;
• an index point on said first rule member proximate to said range scale;
• a target dimension scale, comprising dimension value marks, on said second rule member, said dimension value marks alignable with said mil value marks;
• at least one elevation scale, comprising elevation value marks, on said first rule member;
• a bullet drop scale, comprising drop value marks, on said second rule member;
• said bullet drop value marks alignable with said elevation value marks;
• wherein when said second rule member is controllably moved to align a dimension value mark corresponding to the known dimension with a selected mil value mark on said mildot scale, said index point is aligned with a range value mark corresponding to the distance to the target, and a drop value mark corresponding to the known bullet drop simultaneously is aligned with an elevation value mark corresponding to the adjustment to firearm elevation or windage.

A method, useable with a firearm having a telescopic sight including a mildot reticle and having a known bullet drop or drift value over a known distance, for determining the range to a target of a known dimension and for determining an adjustment to firearm elevation or windage to compensate for bullet drop or drift, the method comprising the steps of:

• a) viewing the target through the scope;
• b) observing the number of mildots apparently occupied by the target to determine a mildot value;
• c) estimating the actual size of the target to determine a target dimension value;
• d) manipulating adjacent mildot and target dimension scales to align respective marks thereon corresponding to the mildot value and the known target dimension value;
• and
• e) viewing the alignment of an index point with a range value mark on a range-to-target scale;
• wherein the step of manipulating adjacent mildot and target dimension scales further comprises automatically simultaneously manipulating a bullet drop scale to align a bullet drop value mark with an elevation value mark, on an elevation scale, corresponding to the adjustment to firearm elevation or windage.