Terminal ballistics is that part of the arrow's travel from when the point strikes the target surface to when it comes to rest. It is of major interest to hunters, but of little importance to others.
Enter the desired range here or in any of several other places.
Enter the uncertainty in the shot-to-shot range estimation. In target shooting this may be due to changes in the archer's position or stance. For hunters it may be due to range estimation errors. The checkbox enables this function.
Enter target height relative to ground where the archer is standing (negative if lower).
Enter the angle that the target slopes relative to the vertical. A typical outdoor butt is inclined backwards by 10° to 15°. For flight or clout archery, usually set to 90° i.e. horizontal.
Changing this angle will influence the group size and score. This is because the archer's performance is related as vertical and horizontal angles of spread at launch. As the target is inclined to the archer's sight-line, the vertical group's projection onto the target increases. This effect is moderated by the long range effect when the launch elevation in increased and consequently the impact angle. (See Clout issues in the Sight panel).
The distance to where the arrow intersects the sight-line. Normally this would be the target range.
Calculated vertical and horizontal trajectory impact offset from target center. The effect of changing any kit parameter by a small amount will show immediately as an offset. Click the Re-Sight button to zero out.
The trajectory angles at impact. The "vertical" is the angle in the vertical plane and horizontal is the angle in the horizontal plane.
The trajectory angle from horizontal at impact, and the Arrow's rotation angle from the trajectory line. The rotation plan is assumed to have the orientation set in the Internal tab.
The vertical and horizontal offset of the point from the trajectory line due to rotation at impact. However as the aim of tuning is to eliminate rotation, this term should be small. In estimating scores, FlyingSticks deliberately ignores this term as the rotational model has not been fully confirmed.
This offset needs to be added to the trajectory offset above for the actual offset of the impact. On impact, the offset point will enter the target with that offset, then depending on target material it is likely to deflect the arrow so that its body passes through the initial entry point. However, the arrow is likely to move towards the trajectory intercept if the bale material allows, thus elongating the entry hole. The scoring line rules apply to the arrow body, not the hole.
Calculated arrow speed and spin at impact.
Calculated momentum at impact = m v where m is the arrow mass and v is the velocity.
Calculated kinetic energy at impact = 1/2 m v2
This is the impact energy density required to initially penetrate a target. It should be used as an indicative figure only as penetration is also dependent on shape factor. For example, a value of 0.1 MJ/m2 is coincided necessary to reliably penetrate skin. Below this figure the target is likely to elastically deform and return, causing the arrow to bounce off. Usually only becomes relevant for small game points.
Calculated likely penetration distance into target. If the Hunting tab is not visible, then a target butt is assumed, otherwise the penetration is based on selected hunting game, where rib thickness is a major factor.
As noted else where the penetration calculation is very much a statistical issue about arrow integrity when striking bone.
The average force applied to the target caused by the arrow's deceleration. This force may seem large but is only applied for 5-10 milliseconds during the rapid deceleration. However, its a great number to miss-use!
Time for arrow to reach target. If the target is missed, it is the time to the arrow crossing the sight-line.
The time from release to when the arrow is heard to impact the target. It is the flight time plus the time taken for the impact sound to return, taking wind speed and direction into account.
The simple 2D line diagram is normally a vertical section of the target butt (in mauve) illustrating the target inclination, the arrow trajectory path (fine grey line), arrow impact, the penetration and the distance from the target aiming point - the little red star on the surface.
The arrow is centered in the display area and the target inclination pivots about the penetration distance along the arrow. The grey trajectory line passes through the arrow's CoG (a grey cross) and intercepts the target where the arrow point would strike with the rotation angle were zero. The angle between the trajectory line and the arrow is the arrow's rotation (pitching) on impact.
The effect of changing any kit parameter by a small amount will show immediately as an offset of the read star. Click the Re-Sight button to zero out.
If the arrow misses the butt, outdoor rounds are assumed to impact the ground and indoor rounds hit the wall. The color changes to brown.
If the impact angle drops more than 45° below the horizontal, or the arrow has reversed direction due to a strong head wind on a high trajectory, it is assumed the arrow has impacted the ground. This is more appropriate for flight archery, where the Range Achieved gives the impact distance from the archer.
The penetration of the target is shown for the current target type. For hunters this the selected game while for target shooters it assumes a typical bale material. If the penetration is greater than the arrow length, it is shown with a small gap between the back of the bale and the arrow's nock.
Side
TopSelect the side (default) or top view. When the Top view is not sensible, the view reverts to the Side view.
The simulation trajectory line is taken at the arrow's center of gravity (CoG). If rotation is present, then the impact point will be in error by the amount of point displacement from the trajectory line on impact. The trajectory line takes into account path deviations due to arrow lift, but not lateral movement on impact due to rotation.
When the point of a rotated arrow first impacts off the trajectory line, there will be a tendency to increase the rotation angle during the rapid deceleration. This will be resisted by the bale. The arrow's final position on the target face will move a little towards the ideal trajectory intercept. The amount of movement depending on the strength of bale material.
In the case of a broadhead striking bone, the physics is far more complicated as the point may be deflected.