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
Rifles, Reloading, Optics, Equipment
Long Range Scopes and Other Optics
Zero Shift caused by light conditions - question for W
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="Guest" data-source="post: 66604"><p>Brown Dog: You will find that if the sun is behind you and less than approximately thirty degrees in the sky, that, it will cause a poi change. As an example, it is 0900, the sun is positioned at about twenty degrees or so at your 5. You range your target and it is at 400 yards. Your data card tells you that you must dial in 8.25 MOA. But because the sun is at its present position, you will now click up .25 minute of angle more; equaling 8.5 MOA. In your situation, with the scope you are utilizing and where you are located on the Earth, you would click up 2 clicks. If the sun were to the left, you would click left one click; and to the right, right one click.</p><p></p><p>Remember that this equation is caused from refractionary and secondary light as it moves through all the lenses in your scope. (Similar to when you place a stick in a pool of water ~ it appears to bend). Remove the light from the equation, (Night Time or you are using a dedicated night vision device) and you will have another change. Everything has an equation. Once you practice a bit for where you are, you will have those answers immediately. </p><p></p><p>Wind is a constant that reacts to airplanes, cars, birds and bullets. It is a molecular mass, and when airplanes hit turbulence it is called hitting the CAT. CAT stands for "Clear Air Turbulence." So it is impossible for it to cause a bullet to rise simply because it is behind it. When the bullet leaves the bore of your barrel, it is arching up. If there is no wind, there is less resistance; but if there is a wind behind you, the bullet will exit the barrel and hit it, and the wind will prevent it from climbing to its full arch. It is the same with a head wind. It must be at or above 5mph to really notice a difference. Precision Shooting Students are taught to disregard head and tail winds. (Old School of thought).</p></blockquote><p></p>
[QUOTE="Guest, post: 66604"] Brown Dog: You will find that if the sun is behind you and less than approximately thirty degrees in the sky, that, it will cause a poi change. As an example, it is 0900, the sun is positioned at about twenty degrees or so at your 5. You range your target and it is at 400 yards. Your data card tells you that you must dial in 8.25 MOA. But because the sun is at its present position, you will now click up .25 minute of angle more; equaling 8.5 MOA. In your situation, with the scope you are utilizing and where you are located on the Earth, you would click up 2 clicks. If the sun were to the left, you would click left one click; and to the right, right one click. Remember that this equation is caused from refractionary and secondary light as it moves through all the lenses in your scope. (Similar to when you place a stick in a pool of water ~ it appears to bend). Remove the light from the equation, (Night Time or you are using a dedicated night vision device) and you will have another change. Everything has an equation. Once you practice a bit for where you are, you will have those answers immediately. Wind is a constant that reacts to airplanes, cars, birds and bullets. It is a molecular mass, and when airplanes hit turbulence it is called hitting the CAT. CAT stands for “Clear Air Turbulence.” So it is impossible for it to cause a bullet to rise simply because it is behind it. When the bullet leaves the bore of your barrel, it is arching up. If there is no wind, there is less resistance; but if there is a wind behind you, the bullet will exit the barrel and hit it, and the wind will prevent it from climbing to its full arch. It is the same with a head wind. It must be at or above 5mph to really notice a difference. Precision Shooting Students are taught to disregard head and tail winds. (Old School of thought). [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Long Range Scopes and Other Optics
Zero Shift caused by light conditions - question for W
Top