Angle Of The Dangle

[Alan Holmes 11]

Ok I may sound really stupid here BUT:

 

Been plinking with my new AA S200 .177 in the garden, it is set up for 30 yards and the garden is only about 15 at a push. So when I am shooting out of the patio doors it inevitably shoots slightly low. However at the same distance I was shooting out of the bedroom window on Sunday and expecting it to be shooting slightly low as usual but it was shooting high, about half and inch??? I have been plinking again tonight from the conservatory and it was shooting low as it usually would, so it has not been knocked or out of 0 in some way.

 

Please could someone explain??

 

Thanks

 

Al

[walshie 2,804]

You always have to use a bit of holdunder if you're shooting down at an angle.

[Alan Holmes 11]

Thanks Walshie I worked that one out, but how can there be such a difference?

[walshie 2,804]

Thanks Walshie I worked that one out, but how can there be such a difference?

 

It's nothing to do with what your gun is zeroed at, it's just physics. the whys and wherefores are a mystery to me though.

[PIL 7]

Thanks Walshie I worked that one out, but how can there be such a difference?

The same as walshie , I don't really understand it but it's to do with gravity (shooting up at angle and shooting down at angle) point of impact shift

[Alan Holmes 11]

Ha ha it just blew my mind a little how i could be so different and with my .22 it is not as noticeable!

 

How does it effect if you are shooting up in to a tree?

 

Im going to have to speak to a Physics teachers to explain as it will bug me!

[barrywhite 282]

Also you may not be allowing for power curve .The gun at 190 bar ,150 bar ,110 bar when shot will have a different points of impact also .You may know about this, just checking .

[Brackenharley 16]

Si Pittaway did a video explaining pellet trajectorys when shooting at angles.

 

http://m.youtube.com/watch?v=nCJad1t3_CI

Edited May 13, 2014 by Brackenharley

[jamesS410 106]

The slightly simplistic answer is that if you shoot on the level and you're zeroed at 30 yards your pellet travels upward in an arc crosses your zero once, potentially at 20-25 yards for example, before falling back to again meet your 30 yard zero. If you're shooting down at an angle the pellet is essentially being assisted by gravity and hence doesn't fall as rapidly and strikes above the aiming point. This effect will vary to a degree with different weights of pellets and also with differing scope heights which would possibly explain the why you .22 behaves differently. The effect of aiming upwards is similar as in the poi will be high but in this case it is due to the pellet effectively travelling less distance horizontally so gravity has less effect over the period of time the pellet is in the air. I hope that makes sense but I'm told I'm better at understanding than explaining.

[Rez 4,957]

Basically give it an inch low, either up hill or down hill.

 

Depending on your set up of course.

[RemyBolt 420]

The length of the shot from an elevated platform will actually be a bit longer (trigonomitary from GCSE's...think hypotinous). So although you may only be shooting 15 yards, with an elevation of 5 yards (generous 1st story window), you'll probably be shooting a total of 16 yards!!! All the difference! haha.

 

Truth is, because of the arched trajectory of an air rifle pellet, the arch will be moving along our hypotinous angle, and the point of contact will be above the expectation. Also, the downward movement and the play with gravity, will effect it hugely. It's no longer moving in a smooth up and down curve on a linear direction forward. It'll be moving downwards, and forewards, and with gravity on it as well.

[ghillies 209]

the tragectry arrives higher at the poi on an angle, the worse the angle and/or further away the more pronounced, e.g. aiming up at 70 degrees you'll be on two dots hi at 30 yar ish (hypotenuese).