Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Hunting
Long Range Hunting & Shooting
Long Range shots - elevation right on always to the right
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Pdvdh" data-source="post: 539837" data-attributes="member: 4191"><p>You'll have to explain yourself with respect to "<strong><em>Only if the shots are fired on the direct N-S Axis.</em></strong>" I've gotta presume you're talking about Coriolis Drift. And I've gotta presume you're of the belief that magnetic directions of fire are the correct parameters to input to calculate the magnitude of Coriolis Drift, based on your recommendation to NVH1 to "<em><strong>Take a compass out to where you are shooting, and shoot a line to Magnetic North</strong></em>." </p><p></p><p>If so, you are misinformed on both accounts, and you're providing errant information, advice, and commentary. </p><p></p><p><u>Firstly</u>, the correct direction of fire for purposes of calculating Coriolis Drift is not the magnetic direction. It's the magnetic direction corrected by the quantity of the earth's magnetic declination at the shooter's location on the surface of the earth. In other words, the magnetic Azimuth of fire must be corrected by the quantity of earth's magnetic declination in order to obtain the true Azimuth of fire. Where I hunt in Alaska, the earth's magnetic declination is 20 degrees east. So if, as you suggested, I set up my target 1000 yds magnetically due north from my position of fire, the actual (corrected) direction (Azimuth) of fire would end up being 20 degrees west of True North, for an Azimuth of 340 degrees. The use of magnetic Azimuth's will result in erroneous calculations of Coriolis Drift.</p><p></p><p><u>Secondly</u>, the magnitude of the horizontal component of Coriolis Drift is essentially the same whether the Azimuth of fire is true North (0 degrees), true South (180 degrees), true East (90 degrees) or true West (270 degrees) from any specific Latitude on the earths surface. And the horizontal Coriolis Drift is essentially zero at the equator for small arms fire, regardless of the Azimuth of fire, and maximized at the north and south poles. My prior calculations were based on a location at 45 Degrees North Latitude - half way from the earth's equator to the north pole.</p><p></p><p>Lastly, and this may hurt..., but 8.8 inches of horizontal Coriolis Drift at 1 mile is neither not measurable, nor insignificant. I only quoted the 2.5 inches at 1000 yards because the original poster was seeking to identify the cause of rightward horizontal bullet drift at 1000 yards. But you did state your contention that "<strong><em>the Coriolis effect is not going to have any measurable effect at ranges of under one mile.</em></strong>" </p><p></p><p>Perhaps you should correct yourself.</p></blockquote><p></p>
[QUOTE="Pdvdh, post: 539837, member: 4191"] You'll have to explain yourself with respect to "[B][I]Only if the shots are fired on the direct N-S Axis.[/I][/B]" I've gotta presume you're talking about Coriolis Drift. And I've gotta presume you're of the belief that magnetic directions of fire are the correct parameters to input to calculate the magnitude of Coriolis Drift, based on your recommendation to NVH1 to "[I][B]Take a compass out to where you are shooting, and shoot a line to Magnetic North[/B][/I]." If so, you are misinformed on both accounts, and you're providing errant information, advice, and commentary. [U]Firstly[/U], the correct direction of fire for purposes of calculating Coriolis Drift is not the magnetic direction. It's the magnetic direction corrected by the quantity of the earth's magnetic declination at the shooter's location on the surface of the earth. In other words, the magnetic Azimuth of fire must be corrected by the quantity of earth's magnetic declination in order to obtain the true Azimuth of fire. Where I hunt in Alaska, the earth's magnetic declination is 20 degrees east. So if, as you suggested, I set up my target 1000 yds magnetically due north from my position of fire, the actual (corrected) direction (Azimuth) of fire would end up being 20 degrees west of True North, for an Azimuth of 340 degrees. The use of magnetic Azimuth's will result in erroneous calculations of Coriolis Drift. [U]Secondly[/U], the magnitude of the horizontal component of Coriolis Drift is essentially the same whether the Azimuth of fire is true North (0 degrees), true South (180 degrees), true East (90 degrees) or true West (270 degrees) from any specific Latitude on the earths surface. And the horizontal Coriolis Drift is essentially zero at the equator for small arms fire, regardless of the Azimuth of fire, and maximized at the north and south poles. My prior calculations were based on a location at 45 Degrees North Latitude - half way from the earth's equator to the north pole. Lastly, and this may hurt..., but 8.8 inches of horizontal Coriolis Drift at 1 mile is neither not measurable, nor insignificant. I only quoted the 2.5 inches at 1000 yards because the original poster was seeking to identify the cause of rightward horizontal bullet drift at 1000 yards. But you did state your contention that "[B][I]the Coriolis effect is not going to have any measurable effect at ranges of under one mile.[/I][/B]" Perhaps you should correct yourself. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Hunting
Long Range Hunting & Shooting
Long Range shots - elevation right on always to the right
Top