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Posted: 6/22/2017 7:20:09 AM EDT
[#1]
Ballistic calculators can compensate for this effect, also lattitude is an important data point.
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Posted: 6/22/2017 7:25:24 AM EDT
[#2]
The coriolis effect is negligible over the time it takes a bullet to travel 2 miles.
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Posted: 6/22/2017 7:25:57 AM EDT
[#3]
It also depends on your position on the planet. Is the speed you listed at the equator?
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Posted: 6/22/2017 7:28:11 AM EDT
[#4]
 Coriolis Effect in Long Range Shooting  Demonstrating how Coriolis effects bullet drop at 1000 yards |
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Posted: 6/22/2017 7:29:16 AM EDT
[#5]
Quoted:
The Canadian's Record kill shot thread got me wondering. With the earth spinning at 1,037 MPH or roughly 460 meters a second, shots fired at 90 and 270 degrees (East and West) would need little if any compensation for this effect. Shots fired at 0 and 180 degrees (North and South) would need the most compensation. How is this effect compensated for in all varying 360 Degrees? Is there a dope book or handheld computer that gives the compensation in 100 yard increments for each and every degree at each and every distance for each rifle and cartridge? How about altitude (thinner air) and barometric pressure (air density)? Is that graphed as well? Shooting east/west can actually affect the bullet (vertically) just as much, if not more than north/south will (horizontally), especially closer to the equator. There are many more factors that can affect a bullet's trajectory to an order of magnitude more than the rotation of the earth (altitude and humidity for example), but unless you've got dope, or already taken shots in the given location/conditions, it's not something that can be dialed in precisely. |
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Posted: 6/22/2017 7:30:03 AM EDT
[#6]
Quote History |
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Posted: 6/22/2017 7:31:08 AM EDT
[#7]
Quote HistoryQuoted:
The coriolis effect is negligible over the time it takes a bullet to travel 2 miles. |
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Posted: 6/22/2017 7:32:13 AM EDT
[#8]
I like the app Shooter for your phone. I'm sure there are many. It uses GPS for conditions in the area and adds it to your bullet data.
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Posted: 6/22/2017 7:53:10 AM EDT
[#9]
Quote HistoryQuoted:
9 seconds is a long time. Quote HistoryQuoted:
Quoted:
The coriolis effect is negligible over the time it takes a bullet to travel 2 miles. |
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Posted: 6/22/2017 7:53:50 AM EDT
[#10]
When I was shooting over 1.5 miles and 5 second bullet flight time, the ballistic calculator showed about 18" correction for coriolis effect. Even so my first shots were like 5 yards off and I had to walk the bullet in until I had the correct dope.
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Posted: 6/22/2017 8:04:55 AM EDT
[#11]
Hitting someone at 3500 yards with a firearm is more luck than skill, IIRC, the last American sniper record holder has said as much.
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Posted: 6/22/2017 8:20:53 AM EDT
[#12]
Quote HistoryQuoted:
The coriolis effect is negligible over the time it takes a bullet to travel 2 miles. N27° lat, 27inHg, 90°, 250otm@2900fps, 8.4sec flight time Firing north = 35" drift right drop zero" Firing south= 35" drift right drop zero" Firing east = 35" drift right drop 115" Firing west =35" drift right 115" high S27° lat all the drift will be to the left. In less dense air all the numbers will be reduced because flight time is shorter. |
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Posted: 6/22/2017 8:31:49 AM EDT
[#13]
Quote HistoryQuoted:
The coriolis parameters acting one location and another 2 miles away are virtually the same. In other words, the difference in angular velocity of two particles separated by two miles on a rotating oblate spheroid with a Equatorial diameter of 7926 miles is essentially zero. It probably would not matter if you were shooting artillery, or rockets, but with a rifle, it does. Imagine being in a uuuge Carousel, you are standing in the middle, spinning at the same rate as someone standing at 10, 20, 30 ,40 and 50, yards away. As they get farther away, even though you are spinning at he same rate, you would need to increase velocity of each throw to hit the person by throwing the ball straight at them, otherwise the impetus imparted by the spin of the Carousel onto the ball would decay at predictable rate, while your target continues to move at the same speed as the Carousel. The Speed of your throw would depend on the how fast the Carousel is moving as well. The faster it is the faster the decay. |
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Posted: 6/22/2017 8:41:48 AM EDT
[#14]
Quote HistoryQuoted:
Are you being nitpicky about the name? Because it would be substantia(for hitting a small target)l over a two mile flight time. N27° lat, 27inHg, 90°, 250otm@2900fps, 8.4sec flight time Firing north = 35" drift right drop zero" Firing south= 35" drift right drop zero" Firing east = 35" drift right drop 115" Firing west =35" drift right 115" high S27° lat all the drift will be to the left. |
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Posted: 6/22/2017 8:50:48 AM EDT
[#15]
Quote HistoryQuoted:
Are you combining spin drift and Coriolis effect? Those numbers are based off 2 miles |
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Posted: 6/22/2017 8:56:20 AM EDT
[#16]
At 2 miles there are so many other much more important variables that come into play that coriolis is almost irrelevant.
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Posted: 6/22/2017 8:58:43 AM EDT
[#17]
Quote HistoryQuoted:
Hitting someone at 3500 yards with a firearm is more luck than skill, IIRC, the last American sniper record holder has said as much. |
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Posted: 6/22/2017 8:59:16 AM EDT
[#18]
Quote HistoryQuoted:
At 2 miles there are so many other much more important variables that come into play that coriolis is almost irrelevant. |
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Posted: 6/22/2017 8:59:18 AM EDT
[#19]
Quote HistoryQuoted:
No spin drift on a 10 twist is 209" by itself and will be to the direction of twist regardless of direction of fire. Those numbers are based off 2 miles I don't think that's accurate. |
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Posted: 6/22/2017 8:59:51 AM EDT
[#20]
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not.
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Posted: 6/22/2017 9:00:18 AM EDT
[#21]
Am I in after CoD references?
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Posted: 6/22/2017 9:01:40 AM EDT
[#22]
Quote HistoryQuoted:
230" of elevation difference from east to west and 35" of drift is irrelevant? If you've made shots in the same position before and have your dope then yes, it's mostly irrelevant. Most super-long shots like this were made after several shots to walk it in. |
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Posted: 6/22/2017 9:02:52 AM EDT
[#23]
Quote HistoryQuoted:
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not. It doesn't affect aircraft (or anything else that is guided) because aircraft can make course corrections mid-flight, while a bullet cannot. |
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Posted: 6/22/2017 9:03:58 AM EDT
[#24]
Quote HistoryQuoted:
Am I in after CoD references? 
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Posted: 6/22/2017 9:05:08 AM EDT
[#25]
Quote HistoryQuoted:
If you were attempting a cold bore shot, no, it's not irrelevant. If you've made shots in the same position before and have your dope then yes, it's mostly irrelevant. Most super-long shots like this were made after several shots to walk it in. |
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Posted: 6/22/2017 9:06:09 AM EDT
[#26]
Quote HistoryQuoted:
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not. |
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Posted: 6/22/2017 9:09:39 AM EDT
[#27]
Quote HistoryQuoted:
230" of elevation difference from east to west and 35" of drift is irrelevant? |
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Posted: 6/22/2017 9:11:20 AM EDT
[#28]
Quote HistoryQuoted:
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not. 
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Posted: 6/22/2017 9:15:56 AM EDT
[#29]
Quote HistoryQuoted:
So you're saying it will always drift 35" to the right due to the C effect no matter the firing direction? I don't think that's accurate. |
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Posted: 6/22/2017 9:19:33 AM EDT
[#30]
Quote HistoryQuoted: Sit on the equator and fire north then fire south Now sit at 2deg latitude and do the same thing. Are you telling me that the 2deg change in latitude will cause my southern shot to shift completely in the opposite direction compared to a firing position ~40 miles away? |
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Posted: 6/22/2017 9:22:07 AM EDT
[#31]
Quote HistoryQuoted:
Yes to the right in the northerm hemisphere, to the left in the southern. You're coming up with 10 times that because of an extra half mile? |
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Posted: 6/22/2017 9:22:46 AM EDT
[#32]
How much does the planets rotation really effect things?
An Airplane doesn't ADD its speed with Earth's rotation. Like flying in the opposite direction, a commercial jet going 500 mph, doesn't cover more distance even though its not bolted to the Earth. It doesn't add 1,000 mph that the Earth is supposedly turning under it. Plus, in your car, as you drive 70-80 mph, a Fly buzzing around doesn't splat into the back of your car's windshield. When it decides to fly after already accelerating while it was resting. |
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Posted: 6/22/2017 9:22:53 AM EDT
[#33]
Quote HistoryQuoted:
While I must admit, I have never shot at 2 miles......I have put enough lead on steel at a mile and beyond to know that I don't see even a tenth of that much affect on my projectiles. Quote HistoryQuoted:
Quoted:
230" of elevation difference from east to west and 35" of drift is irrelevant? That would be an elevation difference of 26" east vs west. About 0.2 mil el to acount for and less than 0.1 drift. |
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Posted: 6/22/2017 9:27:58 AM EDT
[#34]
Yes. It's been tested.
Don't remember what caliber, maybe 7 mag. Guy set up so he could fire 1000 yards east and from the same spot 1000 yards west. Point of impact was (I think) about 1- 1.5 feet difference in elevation. I remember seeing his video of it. |
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Posted: 6/22/2017 9:30:57 AM EDT
[#35]
Quote HistoryQuoted:
How much does the planets rotation really effect things? An Airplane doesn't ADD its speed with Earth's rotation. Like flying in the opposite direction, a commercial jet going 500 mph, doesn't cover more distance even though its not bolted to the Earth. It doesn't add 1,000 mph that the Earth is supposedly turning under it. Plus, in your car, as you drive 70-80 mph, a Fly buzzing around doesn't splat into the back of your car's windshield. When it decides to fly after already accelerating while it was resting. Would its course be effected? yep. Try this, walk fast through a room and drop a ball say 6 inches in front of your chest. Chances are good you will run into the ball before it hits the ground, even though you and it were moving at the same speed when you dropped it. |
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Posted: 6/22/2017 9:31:30 AM EDT
[#36]
Quote HistoryQuoted:
I don't know where you're getting your numbers from but at 1.5 miles my data on my 300 Norma shows the maximum effect coriolis has is .4 mils, or about 21 inches in either East or west direction. You're coming up with 10 times that because of an extra half mile? The numbers are from Applied Ballistics Analytics. |
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Posted: 6/22/2017 9:33:08 AM EDT
[#37]
Quote HistoryQuoted:
That extra half mile almost doubles the flight time. I'd like to know where you're pulling all these numbers from, because they're way out in left (or right) field. |
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Posted: 6/22/2017 9:35:15 AM EDT
[#38]
Quote HistoryQuoted:
Double the flight time doubles the effect, it doesn't change it by an order of magnitude, right? I'd like to know where you're pulling all these numbers from, because they're way out in left (or right) field. Confirmed by AB Mobile |
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Posted: 6/22/2017 9:46:25 AM EDT
[#39]
Quote HistoryQuoted:
9 seconds is a long time. Quote HistoryQuoted:
Quoted:
The coriolis effect is negligible over the time it takes a bullet to travel 2 miles. |
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Posted: 6/22/2017 9:48:14 AM EDT
[#40]
So when I push my Norma load out to 2 miles in AB, I get a max variable of 88 inches due East or west.
Keeping in mind, 2 miles is way too far for that cartridge. It's 77.9 mils of elevation due North, that's artillery fire at that point. What cartridge are you basing your numbers off of, a .308? |
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Posted: 6/22/2017 9:48:24 AM EDT
[#41]
Quote HistoryQuoted:
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not. |
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Posted: 6/22/2017 9:50:15 AM EDT
[#42]
I always hit him in the arm.
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Posted: 6/22/2017 9:50:27 AM EDT
[#43]
Quote HistoryQuoted:
The Coriolis effect is bullshit. If it can affect bullet path then it should also affect airplanes and helicopters even more profoundly...which it does not. 
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Posted: 6/22/2017 9:54:24 AM EDT
[#44]
Quote HistoryQuoted:
Applied Ballistics Analytics Confirmed by AB Mobile Example from their site for .308 at 1000yd gives a vertical change of .14mil or 5". 
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Posted: 6/22/2017 9:54:53 AM EDT
[#45]
Quote HistoryQuoted:
Applied Ballistics Analytics Confirmed by AB Mobile Quote HistoryQuoted:
Quoted:
Double the flight time doubles the effect, it doesn't change it by an order of magnitude, right? I'd like to know where you're pulling all these numbers from, because they're way out in left (or right) field. Confirmed by AB Mobile Confirmed by Shooter as well. |
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Posted: 6/22/2017 10:15:11 AM EDT
[#46]
Quote HistoryQuoted:
Screenshot your tables and post it here. Example from their site for .308 at 1000yd gives a vertical change of .14mil or 5". http://appliedballisticsllc.com/App%20Online%20Guide%20Images/AB%20Analytics/Shot1.JPG  Attached FileAnd AB Mobile, Strelok Pro and Shooter all agree. |
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Posted: 6/22/2017 10:16:10 AM EDT
[#47]
Quote HistoryQuoted:
At 2 miles there are so many other much more important variables that come into play that coriolis is almost irrelevant. Something a lot of people don't think about is you have wind at the ground but also often times a much stronger wind at the apex of the bullet arc. Shooting that far will have your bullet WELL above the trees. You cannot see or easily judge this wind. If you have ever spent any time in a small plane you know there is often a much stronger wind a couple hundred feet up when taking off or landing vs the ground. It was a real eye opening experience shooting at that distance. Fundamentals are the fundamentals. You have to have them, but at that range there are so many factors in play I feel lucky to get a hit. You can have significant dope change just shooting at sunrise/set at 1k alone. Coiroilis is waaaaay on down the list in stuff to worry about when shooting past 1k. |
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Posted: 6/22/2017 10:16:25 AM EDT
[#48]
Quote HistoryQuoted:
Sorry it's on my laptop with no internet so just a snap with my phone. https://www.AR15.Com/media/mediaFiles/83091/2017-06-22-09-236348.JPG
I want to see your table for 2 miles with an 8.4sec flight time. |
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Posted: 6/22/2017 10:18:46 AM EDT
[#49]
Quote HistoryQuoted:
You snapped the example I'll do another |
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Posted: 6/22/2017 10:21:19 AM EDT
[#50]
Quote HistoryQuoted:
If you were attempting a cold bore shot, no, it's not irrelevant. If you've made shots in the same position before and have your dope then yes, it's mostly irrelevant. Most super-long shots like this were made after several shots to walk it in. Quote HistoryQuoted:
Quoted:
230" of elevation difference from east to west and 35" of drift is irrelevant? If you've made shots in the same position before and have your dope then yes, it's mostly irrelevant. Most super-long shots like this were made after several shots to walk it in. |
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