Shooting for groups over a lake.

[jamesdmock]

Now y'all have done it ! I found a place to practice at 600 yards, but it involves shooting over a pond. I thought I had found a "bird nest on the ground" and would never struggle at a match again. Now I read this from folks that I respect and my bubble is burst. James

 

[Uthink Uknow]

Shooooot James; that's a puddle.
I've looked out on the Great Lakes and have seen 1000 foot freighters riding several feet above the water.

 

[Texas10]

A couple of other weather related phenomenon that effects shooting over water. This from years of flying gliders on long cross country flights and in competition. The air around a body of water will rise with sun heating, but sink over the cooler water. This may cause bullets in flight to sink measurably as they fly over the pond as the vertical air movement can sometimes be quite extraordinary (several to tens of MPH in velocity).

Also, on high pressure days, the atmosphere is actually sinking (descending) . This is measurable in todays high performance gliders what with GPS instrumentation, and was documented in glide ratio tests conducted decades ago. Think of a high pressure air system as a scoop of ice cream placed on a plate. As it melts it flows down hill and gradually flattens out completely. A high pressure air mass is actually a mountainous bulge in the atmosphere.

So on high pressure days, I would expect groups to print slightly lower, especially at very long distance as the bullet encounters a persistent downdraft in flight. Not MY groups of course, I don't shoot consistently enough to measure the difference.

 

[XENU]

A couple of other weather related phenomenon that effects shooting over water. This from years of flying gliders on long cross country flights and in competition. The air around a body of water will rise with sun heating, but sink over the cooler water. This may cause bullets in flight to sink measurably as they fly over the pond as the vertical air movement can sometimes be quite extraordinary (several to tens of MPH in velocity).

Also, on high pressure days, the atmosphere is actually sinking (descending) . This is measurable in todays high performance gliders what with GPS instrumentation, and was documented in glide ratio tests conducted decades ago. Think of a high pressure air system as a scoop of ice cream placed on a plate. As it melts it flows down hill and gradually flattens out completely. A high pressure air mass is actually a mountainous bulge in the atmosphere.

So on high pressure days, I would expect groups to print slightly lower, especially at very long distance as the bullet encounters a persistent downdraft in flight. Not MY groups of course, I don't shoot consistently enough to measure the difference.

I have a friend back in Ohio that crashed his hot air balloon when he crossed a small lake and was sucked into the downdraft. He learned his lesson.

 

[MikeMcCasland]

My family has a ranch about 1.5hrs from my house; we shoot across water pretty often. I've never noticed much of a difference, but then again the wind is blowing at least 10-20mph at all times.