Advanced Marksmanship Shooting Over Water

[gasrat]

Just have a few questions pertaining to the area I use to test loads at distance. I am fortunate enough to have a place to test loads at distance in excess of 1,000 yards. This partial of land is flat as a board as they say. However, it's also an old drag strip that was used in the 60's and 70's. The area I'm currently using on the property is basically straight down the old asphalt that the drag strip once operated. I can shoot 804 yards at this location. The issue I have is mirage due to the asphalt. I either have to go very early in the morning or late in the evening to somewhat stay away from the heavy, heavy mirage coming off the asphalt when the sun cranks up.

Now to my question. The owner of this property turned it into a catfish farm many years ago when the drag strip closed. So to the left of my current shooting position is a string of ponds used to raise the fish in. It is also an area I think mirage would not be as bad. Now I have read that a bullet traveling over water will impact high because the gravitational pull is less over water versus over land thus allowing a bullet to impact higher than it would shooting across hard ground. I'm curious to know if that is referring to a larger body of water, or any water?. If I shoot over the three ponds that are in a line, neither of which are no more than 4 feet deep and about 200x200 feet in size, would that amount of water have any affect on the bullet pull, causing it to impact higher versus shooting over straight land? I can extend my shooting ranges out to roughly 1200 yards if I shoot over the ponds. But if the water is going to have an affect on bullet impacts due to gravitational pull as mentioned above, I'll just stick to shooting over top the asphalt and deal with the mirage. Basically what I'm curious about is whether anyone can give me some insight on whether or not shooting overtop the three shallow ponds to the target will have any change on the data I gather versus shooting over hard ground? Any information anyone can provide is much appreciated.

 

[Near miss]

No, you are free to use the ponds, no gravitational difference there whatsoever. And even if there were, it would still cause you problems shooting next to the ponds. The cases about gravitational pull is about oceans, miles deep of water.

In reality, you do not even have to take consideration of any effect caused by earth rotation. Because the shooting direction remains the same, all effects keep the same value and do not cause variance to test results.

But do take notes of sun brightness and direction as well as atmospheric effects to keep track of them (a group hitting lower on a separate day is probably due to air pressure than the bullet batch having a worse BC)

So no problems.

 

[sinister]

I've never heard of that. Crazy.

I'd go ahead and shoot over the ponds. I know of several ranges with water bodies between yard line berms, including Camp Smith in New York.

 

[gasrat]

Thanks for the responses. Much appreciated.

 

[Shootin Stuff]

I would hazard a guess that any image distortion due to mirage/heat haze and effect on bullet path due to the localised rising air currents from the drag strip would create much more unreliable data than shooting over catfish ponds.

Plus you will get some great wind Indications shooting over those ponds too.

But if this is all about data collection and gaining experience then why not do both and compare for some real world results?

 

[gasrat]

I would hazard a guess that any image distortion due to mirage/heat haze and effect on bullet path due to the localised rising air currents from the drag strip would create much more unreliable data than shooting over catfish ponds.

Plus you will get some great wind Indications shooting over those ponds too.

But if this is all about data collection and gaining experience then why not do both and compare for some real world results?

Good info. Thanks. I won’t be back over there until after whitetail season. Usually a family member of the property owner is up there hunting every day of the season, so I don’t wanna go in there shooting, and take the chance of messing up a hunt for them. In my part of Kentucky, it’s a blessing to have such a spot like this 20 mins from the house to test at and not have to drive a hour out of the way to find one. So, I don’t wanna do anything to piss anyone off during deer season and lose my ability to use it… lol

 

[supercorndogs]

Who in the world told you that gravity is different over water, and how in the world did you believe them?

 

[Crankie]

why would gravity be different over water. Bermuda Triangle Logic?

 

[CaptArab]

Bro I'm really curious how you think gravity even works???

Lol

 

[CaptArab]

Shoulda put a basketball hoop on our floating dock by the fish pond. All us redneck whities be Dunkin' Like NBA stars

 

[gasrat]

Bro I'm really curious how you think gravity even works???

Oh I had one for you, but I’ll refrain….

Who in the world told you that gravity is different over water, and how in the world did you believe them?

I read it in the back of a hustler magazine once.

 

[DocRDS]

Gravity does change with altitude, so gravity at SEA LEVEL is stronger than at altitude.

Sea Level to Denver (mile high bby!) is (ft per sec per sec)
32.17404855643
32.157800110016
= 0.01625

The difference is 5 parts in 10,000.
(a 200 lb man is 1.5 ounces lighter in Denver than at Sea Level).
And that's why we don't worry about it. (aka technically true, but only detectable by very sensitive equipment).

 

[308pirate]

Now I have read that a bullet traveling over water will impact high because the gravitational pull is less over water versus over land thus allowing a bullet to impact higher than it would shooting across hard ground.

What you read is bullshit

You're an idiot if you believed it

 

[gasrat]

What you read is bullshit

You're an idiot if you believed it

What about this one. Is it possible to have a shotgun that will shoot so far, a person has to pack salt in with the shot to keep the meat from spoiling until you can walk to get it? Had a old man tell me that once. Don’t know how true it is. What says you?

Also had a guy tell me he had the world record large mouth on the line one night and a damn lightning bug landed on his line and burnt it in to and he lost the fish. You know how hot one of them bugs asses get? It hot enough to melt 15 lb test?

 

[308pirate]

What about this one. Is it possible to have a shotgun that will shoot so far, a person has to pack salt in with the shot to keep the meat from spoiling until you can walk to get it? Had a old man tell me that once. Don’t know how true it is. What says you?

Also had a guy tell me he had the world record large mouth on the line one night and a damn lightning bug landed on his line and burnt it in to and he lost the fish. You know how hot one of them bugs asses get? It hot enough to melt 15 lb test?

I like this guy.

 

[shoobe01]

Gravity does change with altitude, so gravity at SEA LEVEL is stronger than at altitude...

Pretty OT but fun fact I always enjoyed: Gravity at the orbit of the International Space Station (220 miles) is about 90% of what it is at sea level. The weightlessness they experience there isn't zero gravity, but freefall. Not until you get to L1 around 930,000 miles sunward does gravity equalize between the two bodies.

Gravity does vary across the surface of the earth, and is less over oceans, but these are TINY changes, most interesting for understanding the geoid (the shape of the earth; it's not a sphere) and for meso-scale geologists who are interested in what large scale structures are underneath it all, and their composition. Ocean gravity also varies all the time; tidal actions change sea level plenty. I bet even naval gunfire computers ignore it, because it's so variable. But be interesting if not.

Also: sounds like a sort cool range despite the oddities of specular reflection and mirage.

 

[ShevchenkoT]

The gravity force above the soil and the pond is the same, because altitude is the same as well. The problem you'll come across shooting on your range is thinner air above the water than above the soil. So, the bullet drag will be higher and impact will be higher too. Thinner air causes effect of refraction. Eventually it changes your impact. Of course, the larger pond is, the dramatically effect is. But it's not so crucial, impact will change just for 1-2 clicks on 1000 yards.

 

[DocRDS]

Pretty OT but fun fact I always enjoyed: Gravity at the orbit of the International Space Station (220 miles) is about 90% of what it is at sea level. The weightlessness they experience there isn't zero gravity, but freefall. Not until you get to L1 around 930,000 miles sunward does gravity equalize between the two bodies.

Gravity does vary across the surface of the earth, and is less over oceans, but these are TINY changes, most interesting for understanding the geoid (the shape of the earth; it's not a sphere) and for meso-scale geologists who are interested in what large scale structures are underneath it all, and their composition. Ocean gravity also varies all the time; tidal actions change sea level plenty. I bet even naval gunfire computers ignore it, because it's so variable. But be interesting if not.

Also: sounds like a sort cool range despite the oddities of specular reflection and mirage.

Gravity is STRONGER at sea level. (sorry wanted to nip that in the bud right away)
But its the altitude/distance that matters.
There is also the fact that the earth is not perfectly uniform (the moon is REALLY bad--it can bump your orbit out of synch).

If you are in death valley (granted that's below sea level, but find some spot that is a 0 feet elevation) or on the ocean, its distance from the center of the earth that matters.

@ShevchenkoT has it right--there will be more atmospheric conditions that impact ballistics, but they aren't gravity. (thinner air you say? N2 is weight 28, O2 is weight 32, but H20 is weight 18!, more water vapor is THINNER AIR!--of course that percentage is small--but its enough--humidity is a factor in ballistics)

There are a lot of these little fudge factors floating around that get started as rumors.

 

[Fig]

Holy FUCK! Did you hear that bullshit from the gurus on Accurateshooter? Does water put bullets to sleep faster than land? Honestly, that is worse than their sleeping bullet bullshit and the rest of the myths they propagate.

 

[gasrat]

Holy FUCK! Did you hear that bullshit from the gurus on Accurateshooter? Does water put bullets to sleep faster than land? Honestly, that is worse than their sleeping bullet bullshit and the rest of the myths they

Jerry was a race car driver
He drove so goddamn fast
He never did win no checkered flags
But he never did come in last
Jerry was a race car driver
He'd say "El Sob number one"
With a Bocephus sticker on his 442
He'd light 'em up just for fun

 

[shoobe01]

Gravity is STRONGER at sea level. (sorry wanted to nip that in the bud right away)...

Stronger than what? Mean sea level is the baseline for talking about all sorts of stuff, but here gravity variation with altitude, so... what did I say that sounds wrong, or otherwise miss here?

 

[DocRDS]

Gravity does vary across the surface of the earth, and is less over oceans, but these are TINY changes, most interesting for understanding the geoid (the shape of

The bolded part. Not sure where this is coming from, but what mass concentrations (and oceans are like un-mass concetrations) do is throw off the uniformity of the gravitational field (gravity has both strength and direction--mass density would cause the direction to shift away from pure 'down'). The moon is known for this (not oceans, but some parts are more dense) and it can be tracked by the orbital decay/shift over very long periods of time (years).

Here is a recent 'gravity' map (blue less , red more)

Note the range:
Note: one mGal (milligal) is equal to an acceleration of one thousandth of a centimeter per second per second, which is approximately one millionth of the average strength of Earth’s gravity field (980 centimeters per second per second).

English Units is 32 feet per second per second for reference.

 

[308pirate]

The problem you'll come across shooting on your range is thinner air above the water than above the soil.

Prove it

 

[DocRDS]

Meh your Kestrel can pick up the humidity. its part of the DA calc.

But its not like there is 'dry' pockets and 'wet' pockets. Its all one big fluid and any weather measurement will pick it up.

 

[gasrat]

A simple yes or no answer would have been fine to what I asked. Was it a stupid question? Some think so. But I was curious is all as for the reason I asked it. I don’t remember exactly the place I read it. It just got me thinking.

I didn’t know it was gonna turn into a pissing match of intellects trying to prove whose right and whose wrong. I will admit though, after reading the responses, I conclude some of you guys are sharper than rat turds.