Reticle for telescopic gunsight and method for using

• US 6,591,537 B2
• Filed: 03/19/2002
• Issued: 07/15/2003
• Est. Priority Date: 09/14/1998
• Status: Expired due to Term

• Current Assignee: Thomas D Smith, III
• Original Assignee: Thomas D Smith
• Inventors: Smith, Thomas D.
• Primary Examiner(s): Carone, Michael J.
• Assistant Examiner(s): BUCKLEY, DENISE J
• Application Number:
  US10/101,819
• Publication Number:
  US 20020139030A1
• Time in Patent Office: 483 Days
• Field of Search: 421/22, 421/30, 731/67
• US Class Current: 42/122
• CPC Class Codes: F41G 1/38 Telescopic sights specially adapted for smallarms or ordnance telescopic sights in general G02B; Supports or mountings therefor
• CPC Class Codes: F41G 1/473 for lead-indicating or range-finding, e.g. for use with rifles or shotguns
• CPC Class Codes: G02B 23/14 Viewfinders for photographic apparatus G03B13/02
• CPC Class Codes: G02B 27/32 Fiducial marks and measuring scales within the optical system

Abstract

A gunsight reticle defines a system of dimensioned indicia spaced at specific separations to improve aiming accuracy of a rifle. The indicia include perpendicularly intersecting center vertical and center horizontal hairlines, and four horizontal range-marker lines disposed at specific angular separations below the horizontal hairline in bisected relationship with the center vertical hairline. Spacing of the range marker lines below the center horizontal hairline is proportional to bullet drop at selected ranges, depending upon ballistic characteristics of bullet used. Relative lengths of said range-marker bars on each side of the central vertical crosshair are proportional to a cross-wind of 10 mph at target range reflected by respective range marker. The method involves employing this reticle to determine distance to target, and using distance thus determined to ascertain a precise aiming point on the reticle. These indicia also have other useful characteristics that allow the shooter to easily mentally calculate corrections for crosswind, moving target and shooting at targets that are above or below the shooter at a significant angle.

Claims

1. A method of aiming a rifle equipped with a telescopic gunsight having an optical system comprised of a forward objective lens element, a rear eyepiece lens element and intervening erector lens element, said elements being aligned upon an optical axis constituting a line of sight and protectively confined within an elongated tubular housing adapted to be securely affixed to a rifle, a transparent reticle in said optical system between said objective and erector lens elements, said transparent reticle having distance-measuring and aiming indicia, said indicia comprising a center vertical straight hairline and a center horizontal straight hairline, said center vertical and center horizontal hairlines intersecting perpendicularly, and four straight horizontal range-marker hairlines of sequentially incremental length disposed below said center horizontal hairline in vertically bisected relationship with said center vertical hairline, the method comprising:

a) determining the distance to the target employing said reticle, which is placed adjacent to the objective lens, and

b) using said determined distance and said reticle range marker hairlines to ascertain a precise aiming point on said reticle for aiming said rifle at the target.

2. A method of aiming a rifle equipped with a telescopic gunsight having an optical system comprised of a forward objective lens element, a rear eyepiece lens element and intervening erector lens element, said elements being aligned upon an optical axis constituting a line of sight and protectively confined within an elongated tubular housing adapted to be securely affixed to a rifle, a transparent reticle in said optical system between said objective and erector lens elements, said transparent reticle having distance-measuring and aiming indicia, said indicia comprising a center vertical straight hairline and a center horizontal straight hairline, said center vertical and center horizontal hairlines intersecting perpendicularly and each having radially distal portions which are widened to form posts having radially directed innermost and outermost extremities, and four straight horizontal range-marker hairlines of sequentially incremental length disposed below said center horizontal hairline in vertically bisected relationship with said center vertical hairline, the method comprising:

a) determining the distance to the target employing said reticle, which is placed adjacent to the objective lens, and

b) using said determined distance, said reticle range marker hairlines and said posts to ascertain a precise aiming point on said reticle for aiming said rifle at the target.

3. A method of aiming a rifle equipped with a telescopic gunsight having an optical system comprised of a forward objective lens element, a rear eyepiece lens element and intervening erector lens element, said elements being aligned upon an optical axis constituting a line of sight and protectively confined within an elongated tubular housing adapted to be securely affixed to a rifle, a transparent reticle in said optical system between said objective and erector lens elements, said transparent reticle having distance-measuring and aiming indicia, said indicia comprising a center vertical straight hairline and a center horizontal straight hairline, said center vertical and center horizontal hairlines intersecting perpendicularly and each having radially distal portions which are widened to form posts having radially directed innermost and outermost extremities, and four straight horizontal range-maker hairlines of sequentially incremental length disposed below said center horizontal hairline in vertically bisected relationship with said center vertical hairline, the method comprising:

a) determining distance to target employing said reticle;

b) determining correction for wind of known (or estimable) speed and direction;

c) determining correction for magnus and yaw of repose effects on bullet;

d) determining correction for uphill or downhill shooting angle;

e) determining correction for target speed and direction;

f) using said determined distance, estimated wind speed and direction, estimated magnus effect, estimated uphill or downhill angle, estimated target speed and direction, and said reticle range marker hairlines and said posts to ascertain a precise aiming point on said reticle for aiming said rifle at the target with sufficient accuracy to produce the desired shot placement.

4. A telescopic gunsight having an optical system comprising a forward objective lens element, a rear eye-piece lens element and an intervening erector lens element aligned along an optical axis constituting a line of sight and protectively confined within an elongated tubular housing adapted to be securely affixed to a rifle for shooting a bullet at a target, a transparent reticle in said optical system between said objective and erector lens elements, said reticle having distance-measuring and aiming indicia thereon, said indicia comprising a center vertical straight hairline and a center horizontal straight hairline, said center vertical and center horizontal hairlines intersecting perpendicularly, and four straight horizontal range-marker hairlines of sequentially increasing incremental lengths disposed below said center horizontal hairline and parallel thereto and in vertically bisected relationship with said center vertical hairline, the vertical spacing of said range-marker hairlines below said center horizontal hairline being proportional to the drop of said bullet at regularly increased uniform target ranges.

5. A telescopic gunsight as defined in claim 4 wherein said target ranges are 300 yards, 400 yards, 500 yards and 600 yards respectively but where other ranges are appropriate for other types of guns and loads.

6. A telescopic gunsight as defined in claim 5 wherein the spacing of said range marker hairlines below said horizontal center hairline are 2.0, 4.8, 7.5, and 10.5 inches of subtention at 100 yards respectively but where other spacing ratios can be applied to specific other types of guns and loads for special or unique situations.

7. A telescopic gunsight as defined in claim 4 wherein the lengths of said range-marker hairlines on either side of the center vertical hairline are proportional to the effect of a 10 mph wind on said bullet at the respective target ranges but where other lengths can be used for specific other applications.

8. A telescopic gunsight as defined in claim 7 wherein the lengths of said range marker hairlines on either side of the center vertical hairline are 2.06, 2.95, 4.16 and 4.86 inches of subtention at 100 yards respectively but where other lengths can be used for specific other applications.

9. A telescopic gunsight having an optical system comprising a forward objective lens element, a rear eyepiece lens element and an intervening erector lens element aligned along an optical axis constituting a line of sight and protectively confined within an elongated tubular housing adapted to be securely affixed to a rifle for shooting a bullet at a target, a transparent reticle in said optical system between said objective and erector lens elements, said reticle having distance-measuring and aiming indicia thereon, said indicia comprising a center vertical straight hairline and a center horizontal straight hairline, said center vertical and center horizontal hairlines intersecting perpendicularly and each having radially distal portions which are widened to form posts having radially directed innermost and outermost extremities, and four straight Horizontal range-marker hairlines of sequentially increasing incremental lengths disposed below said center horizontal hairline and parallel thereto and in vertically bisected relationship with said center vertical hairline, the vertical spacing of said range-marker hairlines below said center horizontal hairline being proportional to the drop of said bullet at regularly increased uniform target ranges.

10. A telescopic gunsight as defined in claim 9 wherein the lengths of said range-marker hairlines on either side of the center vertical hairline are proportional to the effect of a 10 mph wind on said bullet at the respective target ranges but where other lengths can be used for specific other applications.

11. A telescopic gunsight as defined in claim 9 wherein the distance of the innermost points of the posts on the center horizontal hairline from the center vertical hairline is directly proportional to the speed of a running animal but where other lengths can be used for specific other applications.