For me, it's the same idea as shooting a scoped rifle. In the normal positions (off-hand, benchrest, etc.), the rifle bore, the scope and your eye are all aligned on the vertical plane. Upon firing, the bullet rises to meet the level of the scope and then falls below it but everything stays aligned on the vertical plane due to gravity. So at 0-20 yards, the bullet hits low (bore is below the scope), it may hit high at 100 yards, come down to the scope's zero range at 200 and then fall below again beyond that.
This is basically what happens with an arrow at a 1:00 cant. The arrow starts right under your eye on the vertical plane, rises to meet the level of your eye, rise up a little beyond that (depending on your method) and then begins its descent below. The flat spot of an arrow's trajectory is basically the same as your Maximum Point Blank Range (MPBR) from rifle shooting.
Now imagine that you cant a scoped rifle at an aggressive angle -- say perfectly horizontal. The bore is still pointed at the scope but now gravity won't be bringing it back along the same vertical plane. The bullet angle will now be travelling on the horizontal plane as well since the bullet is travelling toward the center of the scope, which is not above the bore anymore. This is why airgunners and long range shooters affix a level to their scope rail. A small deviation in angle will induce side offset and throw off the shot. I could see the difference in just 17-18 yards with an airgun with a high-mounted scope. Side mounted scopes on older lever-action winchesters, Mosins, some AKs face the same issues.
Back to archery, once you're canting from various angles, the arrow is no longer under your eye. Your arrow (bore) is offset from your eye (scope) and adjustments will need to be made to counteract this offset. The arrow is travelling toward your eye but, since your eye is to the side and over the arrow (diagonal in most cases), the arrow will continue on that sideways path and your shot will go off to the side.
To counteract this, I shoot with 2 gaps: one for that 1:00 position. Another for about 60-70 degrees off vertical (nearly horizontal) for when I'm seated on the ground or need to shoot under a branch. My anchor & alignment is a little different but the vertical gaps are pretty close to the same either way. I just put my arrow tip about 10" to the left of my bullseye and aim a tad higher (lose about 2-yards of trajectory). I've not messed with it much past 20 yards since that's my max hunting range.
The few times I've done 3D, I made a self-imposed rule of no standing shots on turkeys. Learning to shoot between tree limbs, grass, bushes, etc. and accounting for 2 planes of trajectory is a challenge but a fun one.
Topic: Bow cant explained, please (Read 4104 times)
