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
Chatting and General Stuff
General Discussion
Bubble level for rifle
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="Brent" data-source="post: 41000" data-attributes="member: 99"><p>Phil,</p><p>You misunderstand the numbers in Dave's sreen shots at 90 degrees cant I think. </p><p></p><p>If you look back to the ones I posted, you'll see where your misunderstanding is.</p><p></p><p>The first number in Dave's example above is "0" because the LOS and BL (bore line) is on the same plane, they both are level. His scope height is not zero, but 2.6" or 1.83" depending on which one above you look at. Both are canted 90 degrees and on the same plane now, so effective scope hight in the vertical plane is "zero inches", the number to the left ouside the parenthesis. At 6 degree cant, my example resulted in 1.99" in the vertical plane. Scope height is (2.0" @ 6 deg). Make more sense now?</p><p></p><p>The way I see this, or imagine it is, the LOS is straight throught the center of the bull, the BL drop is straight through the bull as well (dialed in at 100 yards for example), and this draws a circle under the bull when the rifle is rotated around the LOS, with 6 O'clock being 6 MOA low, 3 and 9 O'clock being diagonal to 12 and 6 O'clock. Picture a bent wire in the shape of the trajectory ending at 100 yards, with a weight hanging on the "end" of it so gravity keeps muzzle exit and the 100 yard point and all points in between aligned in the vertical plane when you rotate the rifle around LOS axis, and while the wire rotates in the bore. Follow? </p><p></p><p>Canting to the right (LOS maintained on bull remember) rotates the bore and wire to the left and begins to lower it at the same time until you hit 180 degrees, then it moves to the right and back up again. The closer to 12 and 6 O'clock you are, the higher the rate of deflection per degree is realized, but less rate in drop. The closer to 3 and 9 O'clock you are the opposite is true, more drop per degree of rotation and less deflection on the horizontal plane there is. So horizontal deflection is greatest per degree where we normally hold at 12 O'clock. At 90 degrees, vertical deflection from cant is what you will see more than anything, and horizontal deflection would be little at that point. </p><p></p><p>Consider the imaginary circle it draws, horizontal deflection is more pronounced in the first 45 degrees of cant than it is in the second 45 degrees where vertical deflection is now greatly being increased.</p><p></p><p>The same thing goes for wind deflection at near 12 and 6 O'clock directions. Each degree of wind direction change will prove "more" significant to horizontal deflection than it would had the wind direction been near 3 or 9 O'clock. Wind speed changes will however have less efects at 12 and 6 O'clock and more effect at 3 and 9 O'clock. </p><p></p><p>I missed a couple things in Dave's screen shots (read too fast) I'm now seeing, namely the inches of deflection being very oddly different, and the 100 yard deflection. </p><p></p><p>I will get Jim on here hopfully to explain what we're seeing, and if there is a bug causing this or what. I talked to him last night, but just now see this problem. I'll send him a link to the thread. </p><p></p><p>Heading to the range...</p><p></p><p>[ 03-07-2004: Message edited by: Brent ]</p></blockquote><p></p>
[QUOTE="Brent, post: 41000, member: 99"] Phil, You misunderstand the numbers in Dave's sreen shots at 90 degrees cant I think. If you look back to the ones I posted, you'll see where your misunderstanding is. The first number in Dave's example above is "0" because the LOS and BL (bore line) is on the same plane, they both are level. His scope height is not zero, but 2.6" or 1.83" depending on which one above you look at. Both are canted 90 degrees and on the same plane now, so effective scope hight in the vertical plane is "zero inches", the number to the left ouside the parenthesis. At 6 degree cant, my example resulted in 1.99" in the vertical plane. Scope height is (2.0" @ 6 deg). Make more sense now? The way I see this, or imagine it is, the LOS is straight throught the center of the bull, the BL drop is straight through the bull as well (dialed in at 100 yards for example), and this draws a circle under the bull when the rifle is rotated around the LOS, with 6 O'clock being 6 MOA low, 3 and 9 O'clock being diagonal to 12 and 6 O'clock. Picture a bent wire in the shape of the trajectory ending at 100 yards, with a weight hanging on the "end" of it so gravity keeps muzzle exit and the 100 yard point and all points in between aligned in the vertical plane when you rotate the rifle around LOS axis, and while the wire rotates in the bore. Follow? Canting to the right (LOS maintained on bull remember) rotates the bore and wire to the left and begins to lower it at the same time until you hit 180 degrees, then it moves to the right and back up again. The closer to 12 and 6 O'clock you are, the higher the rate of deflection per degree is realized, but less rate in drop. The closer to 3 and 9 O'clock you are the opposite is true, more drop per degree of rotation and less deflection on the horizontal plane there is. So horizontal deflection is greatest per degree where we normally hold at 12 O'clock. At 90 degrees, vertical deflection from cant is what you will see more than anything, and horizontal deflection would be little at that point. Consider the imaginary circle it draws, horizontal deflection is more pronounced in the first 45 degrees of cant than it is in the second 45 degrees where vertical deflection is now greatly being increased. The same thing goes for wind deflection at near 12 and 6 O'clock directions. Each degree of wind direction change will prove "more" significant to horizontal deflection than it would had the wind direction been near 3 or 9 O'clock. Wind speed changes will however have less efects at 12 and 6 O'clock and more effect at 3 and 9 O'clock. I missed a couple things in Dave's screen shots (read too fast) I'm now seeing, namely the inches of deflection being very oddly different, and the 100 yard deflection. I will get Jim on here hopfully to explain what we're seeing, and if there is a bug causing this or what. I talked to him last night, but just now see this problem. I'll send him a link to the thread. Heading to the range... [ 03-07-2004: Message edited by: Brent ] [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Chatting and General Stuff
General Discussion
Bubble level for rifle
Top