Wind

[Rickenbacker]

Just had a quick look at Chairgun, on the windage it seems to make no allowance for POI elevation changes due to rifling direction as per an earlier thread discussion. So maybe not that accurate ?

Furthermore, chairgun would replicate an open space with constant horizontal wind from muzzle to target, based on the BC of an unfired pellet (unchanged by rifling groves and air-blast re-shaping)...

The true measure of a pellet's BC out of your gun is chrono' at the muzzle, and another chrono' downrange (without wind).

Chairgun is probably better for BC comparison than it is for working out drift in inches at a given range...

Of course, there's little point in using a pellet that gives the best BC, if that pellet doesn't happen to group well in your gun... same as there's little point to using a pellet (or calibre) that looses you more through pronounced trajectory than it gains in reduced windage drift...

It's also (perhaps) interesting that a vertical component to wind causes the same degree of vertical pellet deflection as horizontal wind does to the horizontal. Which is much greater than the more minor elevation effects of horizontal tail or head wind, with or without the (also minor) effects of direction of spin vs cross-wind direction.

Now my head hurts...

Have you tried Brian Samson's excellent 'wind game'? http://www.shooting-the-breeze.com/f...ad.php?t=21800

[TonyL]

Excellent stuff, young Phil.

And, Yep, played Brian's game a few months ago.



Now, admittedly not that scientific, nor conclusive, but many years ago I was shooting with a club member and it was hellishly windy that day. Normally Derek's .22 '80 grouped very tightly. On this particularly rough day, his Wasps were all over the place, whereas my 10.5gr H&N Silhouettes were awesome.

Apparently there's a heavier JSB made pellet with a BC superior to the newer H&N Barracuda. If they suited the shooter's barrel, I could only guess that these would be utterly superb in terms of velocity retention, long range trajectory and cheating the wind.

[tommahalk]

Wouldn't it make sense to say the most efficient pellet is the pellet which is least likely to be moved as Mutch in the wind?