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Quoted:
I guess they just don't teach this shit anymore. You can inject modern precision bullets with different gases to change their performance. That's what that little hole in the tip is for on the OTM bullets. You can put helium in there to make the bullets rise more, or you can put something like carbon dioxide or sulfur hexafluoride in there to make the bullets drop faster, depending on what you're wanting to do. You have to be careful to not stick the needle in too far or you'll cause a leak and the gas won't stay in there. There's a PDF guidebook on how to choose the right gas and how to inject it properly. Should help you out, OP. Do a bit of searching it was linked here a while back. View Quote |
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*like
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Quoted:
I see a lot of bullet drop compensation computations but cant recall seeing a bullet rise computation. With gravity being less effective at really high altitudes above sea level (10k' or more), I would think that we should have a book to help shooters account for this. View Quote Mike |
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Ah shit. I forgot about helium rounds... View Quote View All Quotes View All Quotes Quoted:
Quoted:
I guess they just don't teach this shit anymore. You can inject modern precision bullets with different gases to change their performance. That's what that little hole in the tip is for on the OTM bullets. You can put helium in there to make the bullets rise more, or you can put something like carbon dioxide or sulfur hexafluoride in there to make the bullets drop faster, depending on what you're wanting to do. You have to be careful to not stick the needle in too far or you'll cause a leak and the gas won't stay in there. There's a PDF guidebook on how to choose the right gas and how to inject it properly. Should help you out, OP. Do a bit of searching it was linked here a while back. Test it for us OP, for science! |
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https://en.wikipedia.org/wiki/Gravity_anomaly
The Bouguer anomalies usually are negative in the mountains because they involve reducing out the attraction of the mountain mass, by about 100 milligals per kilometre of mountain height. In large mountain areas, they are even more negative than this because of isostasy: the rock density of the mountain roots is lower, compared with the surrounding earth's mantle, causing a further gravity deficit. Typical anomalies in the Central Alps are -150 milligals (-1.5 mm/s²). Rather local anomalies are used in applied geophysics: if they are positive, this may indicate metallic ores. At scales between entire mountain ranges and ore bodies, Bouguer anomalies may indicate rock types. For example, the northeast-southwest trending high across central New Jersey (see figure) represents a graben of Triassic age largely filled with dense basalts. Salt domes are typically expressed in gravity maps as lows, because salt has a low density compared to the rocks the dome intrudes. Anomalies can help to distinguish sedimentary basins whose fill differs in density from that of the surrounding region - see Gravity Anomalies of Britain and Ireland for example. |
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I just use the same chart but change all the - into +. Thousand yards with my .308 is tough unless you dig a trench?
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Quoted:Which is less than 1/10th of 1% at altitudes available on this planet. So lets just call it "constant" ok? Frickin' physicists are always trying to distribute their useless, negligible minutia. View Quote Generally, this is a better approach that strutting and swaggering and yelling and arguing and name-calling and all the other techniques normally employed on GD. |
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Anyone who reads GD regularly knows that science is bullshit.
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Quoted:
I see a lot of bullet drop compensation computations but cant recall seeing a bullet rise computation. With gravity being less effective at really high altitudes above sea level (10k' or more), I would think that we should have a book to help shooters account for this. View Quote Gravity works even in orbit. Satellites are fallin, not rising, what would make you think a bullet rises? |
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Coriolis Effect.
If you are on a high enough mountain, and shoot in the right direction, a .257 Weatherby will go into orbit. |
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I'm sure the left handed Benjaminites accounted for altitude in their sling use. OTOH, I think that if one were simply to fire their rifle upside down, this whole optics axis, bore axis thing would be taken care of.
I'm in California so can't easily check, but could our comrades in New Jersey check to see if their boogers change as they drive across the state? |
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I believe you are mistaken sir. Anyone that reads GD regularly should know that bullshit is science! View Quote View All Quotes View All Quotes |
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ITT we learn that OP has a lot of extra time on his hands, and doesn't understand physics.
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View Quote View All Quotes View All Quotes Quoted:
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Does anyone have a bullet rise chart? In pdf or a spreadsheet that i can put my elevation in and get the proper rise calculated? https://www.ar15.com/media/mediaFiles/203937/Graph_20180705A-597944.jpg 45 gets out therr, lol |
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Gravity does affect bullet drop but isn't the only thing.
A 55gr m193 at 3250fps out of a 1/7 twist barrel is rotating at ~334,000rpm. Gyroscopic stabilization affects trajectory, to some extent counteracting the gravitational effect. Additionally. The presence of a treadmill at any point in the projectile's flight will deflect the bullet in unpredictible ways. Lastly, the Bernoulli effect created by the rapidly moving projectile creates lift, also slowing acceleration towards the ground. So calculating bullet drop is much more complex than a simple gravitational acceleration. |
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Quoted: Im giving you a double What happens in real life does not always correlate to what the guy in the wheelchair tells us it is View Quote Gravity is dependent on the separation of the two bodies. The difference is immaterial until you get miles ABOVE the Earth. But since the Earth is not a perfect sphere, the actual force is a bit off the average 9.8 m/s2. So figure it's 9.8000000000000000000000000002 at the ocean and 9.80000000000000000000000000000001 on Everest. Bullets do not rise. |
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View Quote |
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... this thread is a complete waste of bandwidth. There's almost zero value in it
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Quoted:
I see a lot of bullet drop compensation computations but cant recall seeing a bullet rise computation. With gravity being less effective at really high altitudes above sea level (10k' or more), I would think that we should have a book to help shooters account for this. View Quote what kind of pitch/yaw indicators do you use? |
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I'm sitting at around 300' elevation.
I would not be buying the book OP proposes. |
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OP is absolutely correct. It is possible to achieve projectile rise; once I tested this by using helium in my air rifle. I tried to duplicate the results with hot air but when I lit the propane at the muzzle it melted my pellets.
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OP is ferreting out people that can do nothing but regurgitate statistics from socialist educators without doing a BIT of original research.
THE SCIENCE IS NEVER SETTLED, PEOPLE |
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Quoted:
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Does anyone have a bullet rise chart? In pdf or a spreadsheet that i can put my elevation in and get the proper rise calculated? https://www.ar15.com/media/mediaFiles/203937/Graph_20180705A-597944.jpg 45 gets out therr, lol |
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And another thing-the Earth has a rotational speed at the equater of about 1,000 mph.
So if you climb to the top of a really high mountain you will be flung into space by centrifugal force. That's why nobody lives on top of those mountains even though the street value of all that pure snow must be incredible. |
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