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
Leveling the Scope Reticle for Long Range Rifles
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="paphil" data-source="post: 774391" data-attributes="member: 17745"><p>I don't know of any barrel makers that make left twist but I've heard of some European guns that have Left twists. The problem is the same only in the opposite direction. Spin drift is not the same in all bullets and calibers but as best as I can tell, it is between 6 and 12 inches at 1000 yards depending on the twist speed and the shape of the bullet. Coriolis is an addition to or subtracted from the spin drift depending on direction of flight of the bullet and the time of flight. Shooting east will cause the bullet to hit high because the earth and the target are falling. about 3 inches at 1000 yards with a 7mm vld. shooting west is just the opposite . The earth and the target are rising and the bullet will hit low, again about 3 inches. Shooting north and south is still a question in my mind, but if the target is moving with the earth, it would move left to right looking north and right to left shooting south. Still about 3 inches for a 7mm vld with mv of 3000 fps. All of this is very hard to prove due to other environmental issues but I'm sure there is a mathmatical solution. This is all based on time of flight so slower bullets and longer shots will have more effect. Maybe there is someone with artillary backround that could post their thoughts! Not many guns shoot well enough to tell these small effects but when you add them all togather it makes those shooter programs look pretty handy.</p></blockquote><p></p>
[QUOTE="paphil, post: 774391, member: 17745"] I don't know of any barrel makers that make left twist but I've heard of some European guns that have Left twists. The problem is the same only in the opposite direction. Spin drift is not the same in all bullets and calibers but as best as I can tell, it is between 6 and 12 inches at 1000 yards depending on the twist speed and the shape of the bullet. Coriolis is an addition to or subtracted from the spin drift depending on direction of flight of the bullet and the time of flight. Shooting east will cause the bullet to hit high because the earth and the target are falling. about 3 inches at 1000 yards with a 7mm vld. shooting west is just the opposite . The earth and the target are rising and the bullet will hit low, again about 3 inches. Shooting north and south is still a question in my mind, but if the target is moving with the earth, it would move left to right looking north and right to left shooting south. Still about 3 inches for a 7mm vld with mv of 3000 fps. All of this is very hard to prove due to other environmental issues but I'm sure there is a mathmatical solution. This is all based on time of flight so slower bullets and longer shots will have more effect. Maybe there is someone with artillary backround that could post their thoughts! Not many guns shoot well enough to tell these small effects but when you add them all togather it makes those shooter programs look pretty handy. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Chatting and General Stuff
General Discussion
Leveling the Scope Reticle for Long Range Rifles
Top