Tool screams differently according to Neil if you go at him from a different angle as well... Neil screams differently depending on the angle of Neil in a shower cubicle.
(keep it responsible guys
But the rifleman's rule here
gives the info. Note it's a theory that works in maths in a vacuum but has found to follow in reality... but always worth a check.
Cosine indicators will be the new toy of 2012. Here's my cheapie one, as just learning the ratios and having a good estimation will see you good. (not easily done, most over estimate angles). Useful if you are shooting downhill to the bottom of a tree and can't range on the top of the tree because of the leaves.
The main area for concern is where your trajectory changes a lot, so close in, and far away.
Here's a scope mounted one here
But at £85 i am hoping an FT engineer can knock me one or two up