costas, it really depends which distance you shooting the most. the last couple of tries almost invariably where at 122 meters and i feel more confident with that now than most other distance so it boils down to the distance you shoot most, however the windchart i made up is very accurate. hopefully being home for christmas i will have time to edit the video i filmed and all that so i can finally post it.

with regards to the other post on wind, it is very seldom that wind will be constant so either go in a place where the wind will be behind you or atleast at 30 degrees from you so it will only effect you by 1/2 and if you miss, you only miss by half the drift that you would have thought which might still result in a hit. when you look at the wind try to establish the amount of seconds for which the wind seems to be constant, might be 8-10 seconds and then change. this depends on terrain. where i shoot i usually get about 6seconds of constant wind then it slows down or gusts and then seems to go back to normal.
what i do is to take the average speed, work out drift and dial in for that, wait till i have that same condition for a period of atleast 5 seconds and take the shot. by practice you'll get good at that. should be doing more shooting when im home this week