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Old 14th October 2014, 12:17 PM
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EELS EELS is offline
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Join Date: Feb 2011
Member of: Kent Woodsmen FTC
Location: Kent
Posts: 169

Originally Posted by simona View Post
You have to be very careful. The regular dialling we do is a product of two things, the pellet drop and the offset between the line of sight and barrel. An illustration of this is to take the example of two rigs which are identical except that one has a 2.5 inch offset and the other has a 3.5 inch offset.

On the flat the number of clicks between say 42 and 50 yards will vary between these rigs, though the pure drop of the pellet between these distances will be identical. The clicks are different as the rigs have different line-of-sight to barrel offsets.

If you shot both of these rigs at a target 50 yards away, but inclined such that the distance perpendicular to gravity was 42 yards, the click compensation for height (the number of clicks subtracted from the 50 yard value) will be identical on each rig as only pellet drop is affected by target angle not line-of-sight to barrel offset. Clicks equal to the pellet drop difference between 42 yards and 50 yards at 50 yards will have to be subtracted. This is not the same as dialling for 42 yards as only one of the two factors we dial for is changing.

The component of dialling concerned with reconciling the line-of-sight to barrel offset (the bit that varies between the rigs) is only affected by distance from muzzle to target - the elevation of the target will not affect this. The other component of dialling, related to pellet drop, is identical between the rigs so the compensation will also be identical.

Be especially careful on steep close targets; for example itís no good dialling for 10 yards on a mega high 13 yard target as most of this dialling difference is just to close the line-of-sight to barrel offset, what you need to do is subtract an elevation value equal to the tiny difference in actual pellet drop between 10 and 13 yards. In reality this is so tiny as to be meaningless!
Simon Ayres; not only an amazing shot but also a closet physics/mathematics/ballistics lecturer....who knew!

In practical personal the worlds in Italy 2011 on day 1 lane 1 we were confronted by 2 x 50+yd targets at the top a slope I would suggest you'd have needed crampons and an ice axe to climb. Right, thinks I "give em normal clicks and aim low"...dink, dink
Day 2, lane 1, same again. Right, thinks I, "aim high" (maybe it goes the other way over a certain angle?)...dink, dink
Day 3, lane 1, after a few beers the night before and upon hearing of my difficulties, smart-alec Rob Walker tells me "I've nailed them both on both days..straight down the throat.." Well, thinks I, I'm fresh out of options here, straight down the throat it is...flop, flop!

In Germany in 2013, I tied myself up in knots with the angles (there were alot of them with small kills). Then on day 3 whilst contemplating a 15mm kill placed about 14 yards directly above my head, a passing Italian friend pauses to frown at my scorecard. When I explain the problem he helpfully advises that I should "go straight at them!". Again with nothing to lose I take his advice and as with Robs advice, over they go...but too late.

In short we tie our selves up in knots about these things but FT is all about managing variables to within the tolerance of a kill zone - hence they're circular shape!
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