Thread: FT scope set up
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Old 17th May 2016, 06:04 PM
Adam Adam is offline
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Join Date: Jan 2009
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Originally Posted by RobF View Post
Erm not quite.

The top of the trajectory, the apogee is the muzzle. Everything further out is below this. It starts falling as soon as it leaves the barrel (assuming the barrel is horizontal)

If you change the scope height, you do move the tangent point, where the line of sight coincides with the trajectory, further out. It touches once. You can then chose to move zero down, so it touches twice, before and after the tangent point.

In reality, for FT shooters with a normal scope height, the tangent point is between 25-30 yards, and that won't change unless the speed is increased or the scope height is changed. That's where people set 0 to, and then dial up for ranges closer or further away. Of course you could put 0 at 35 yards, and dial up for ranges further away, dial down for closer ones, then dial back up for closer ones even still... but that, most would say, would be daft.

The point of percieved top of trajectory is defined by the pellet's trajectory and scope height. Which is what Brian worked out a long time ago in a post far far away.
Ah, but! Assuming barrel is horizontal which it almost never is. If you are trying to hit a target on the same level as the sight line (and at the far zero point) the sight line is horizontal but the barrel points slightly upwards in order for the pellet to be launched at the correct angle to come back down.
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