rcdinaz Report post Posted August 17, 2015 I completely under stand the whole velocity and BC querks. Also understand the chronograph error. Just was curious as to how much difference you guys were having to enter (if any) based on chrono readings or shooter apps. My first load for my gun I had to adjust slightly than what my chronograph said. Haven't got my new load tested out to 1000 for verification just yet. Although I did take a shot at my 12" gong at 1086 yards the other day with initial values entered and hit it. Soooo I'm close. The last one I did for a 7 Rem Mag I had to bump the Velocity up 70 FPS. from the chronograph readings. I can't recall exactly now but I think mine was 40fps which put it back on course for 500 yds & 700 yds. I have never touched it since the day I made those changes and it has hit its target ever since. Share this post Link to post Share on other sites
Randall Report post Posted November 10, 2015 I also have the G7, and really like it. The only problem was packing it around with me in the field. I contacted FHF for a case, and his is still in production. I found a perfect fitting case at Sportsmans for 8.99 . It's the Fieldline pro series electronic's and optics case, perfect fit. Share this post Link to post Share on other sites
n2horns Report post Posted November 11, 2015 better off being more on target at longer ranges than close ranges. Inside 400 yds is a wash, better be nuts on at 1k. Bob Beck did one of his shows on dialing to 1k in 21 bullets, using BR2. Watch it, he is playing with velocity to make longer range corrections. 1 Share this post Link to post Share on other sites
308Nut Report post Posted November 11, 2015 Everyone north of the equator the shot will always be right no matter which way you are facing due to coriolis. That is not exactly accurate. (pun intended) Coriolis is pretty complicated when it comes to figuring exact displacement of a shot. For example... it has more of an effect near the equator than it would near a pole (North or South), a shot directly north or south will print substantially more movement then one fired directly east or west. Spin drift is more of a constant, but can change with altitude/air density. I feel when speaking about the vast majority of "long range shooters" .3 MOA deviation at ranges of or exceeding 1000 yds would be EXTREMELY hard to pin down to one culprit or eliminate. An even slightly canted scope or rifle could easily be responsible for 1/2 MOA deviation, not to mention the multitude of other factors like wind, mirage, air density, spin drift, etc, or a loose nut behind the trigger. If a guy controls what he can, and coriolis was the only thing unaccounted for then he will likely hit close enough in any hunting situation. I watch lots of long range hunting shots being made (youtube, DVDs, and TV) where coriolis is the least of the guys worries. I guess what I am trying to say is if you do your due diligence at the range and at the loading bench, coriolis will not effect anything but serious extreme range shooting. BIGBROWNS, Thanks for posting. I hope you get that last little bit worked out and put the hammer on a bear! A few key points regarding the Coriolis effect. Fact: There is a greater horizontal effect the closer you get to the poles. Fact: The horizontal effects become less as you get closer to the equator. Fact: Shots east and west yield a vertical component. Fact: Projectiles fired in the Northern Hemisphere will always appear to drift right regardless of direction of fire and left in the Southern Hemisphere. Fact: shots north and south show nearly the same horizontal deviation as those east and west. If you were 500 yards south of the equator shooting across it to a target 500 yards north of the equator, there would be zero effect. Share this post Link to post Share on other sites
WampusCat Report post Posted November 17, 2015 Fact: I wrote it backwards somehow when speaking about the effects at the poles vs the equator. Good catch and thanks for the keeping me honest While the rest of your information looks good I still don't think any of this will be a factor at hunting ranges. Even at 800-1000 yards with modern high velocity projectiles. I think Coriolis gets turned into a buzz word that gets thrown around in shooting circles. It absolutely exists and is necessary for an extremely small niche of extreme distance guys. The kicker is do the gadgets discussed in the thread actually calculate (correctly) for the equation(s) necessary to make an absolute correction? At what range (distance) have you experienced Coriolis alone shifting your point of impact more than 1 or even .75 MOA? Share this post Link to post Share on other sites
308Nut Report post Posted November 17, 2015 Fact: I wrote it backwards somehow when speaking about the effects at the poles vs the equator. Good catch and thanks for the keeping me honest While the rest of your information looks good I still don't think any of this will be a factor at hunting ranges. Even at 800-1000 yards with modern high velocity projectiles. I think Coriolis gets turned into a buzz word that gets thrown around in shooting circles. It absolutely exists and is necessary for an extremely small niche of extreme distance guys. The kicker is do the gadgets discussed in the thread actually calculate (correctly) for the equation(s) necessary to make an absolute correction? At what range (distance) have you experienced Coriolis alone shifting your point of impact more than 1 or even .75 MOA? Coriolis alone? Unfortunately as you know there is another factor at play here regarding horizontal impacts. That is spin drift. You can't test how much only one or the other will be. The only way to separate the two is math. The math says my Coriolis is roughly 3" at a grand at 61 degrees N. Around Phoenix it's roughly 1/2 the drift at 33 degrees N. My combined (mathematically and real world at 31 degrees) is 8" to 11" at a grand right depending on the rifle and load I'm using. I start to notice it at 550 yards and by 700 it's very noticeable. Share this post Link to post Share on other sites
WampusCat Report post Posted November 17, 2015 Coriolis alone? Unfortunately as you know there is another factor at play here regarding horizontal impacts. That is spin drift. You can't test how much only one or the other will be. The only way to separate the two is math. The math says my Coriolis is roughly 3" at a grand at 61 degrees N. Around Phoenix it's roughly 1/2 the drift at 33 degrees N. My combined (mathematically and real world at 31 degrees) is 8" to 11" at a grand right depending on the rifle and load I'm using. I start to notice it at 550 yards and by 700 it's very noticeable. Interesting. Is that spin drift and coriolis? with 308? Share this post Link to post Share on other sites
308Nut Report post Posted November 17, 2015 Yes sir. The math indicates 3" for Coriolis alone at 1000. The balance is spin drift which is much more. Total is 8-11" depending on what I'm shooting on a given day. Share this post Link to post Share on other sites
willhunt4coues Report post Posted November 17, 2015 Everyone north of the equator the shot will always be right no matter which way you are facing due to coriolis. That is not exactly accurate. (pun intended) Coriolis is pretty complicated when it comes to figuring exact displacement of a shot. For example... it has more of an effect near the equator than it would near a pole (North or South), a shot directly north or south will print substantially more movement then one fired directly east or west. Spin drift is more of a constant, but can change with altitude/air density. I feel when speaking about the vast majority of "long range shooters" .3 MOA deviation at ranges of or exceeding 1000 yds would be EXTREMELY hard to pin down to one culprit or eliminate. An even slightly canted scope or rifle could easily be responsible for 1/2 MOA deviation, not to mention the multitude of other factors like wind, mirage, air density, spin drift, etc, or a loose nut behind the trigger. If a guy controls what he can, and coriolis was the only thing unaccounted for then he will likely hit close enough in any hunting situation. I watch lots of long range hunting shots being made (youtube, DVDs, and TV) where coriolis is the least of the guys worries. I guess what I am trying to say is if you do your due diligence at the range and at the loading bench, coriolis will not effect anything but serious extreme range shooting. BIGBROWNS, Thanks for posting. I hope you get that last little bit worked out and put the hammer on a bear! A few key points regarding the Coriolis effect. Fact: There is a greater horizontal effect the closer you get to the poles. Fact: The horizontal effects become less as you get closer to the equator. Fact: Shots east and west yield a vertical component. Fact: Projectiles fired in the Northern Hemisphere will always appear to drift right regardless of direction of fire and left in the Southern Hemisphere. Fact: shots north and south show nearly the same horizontal deviation as those east and west. If you were 500 yards south of the equator shooting across it to a target 500 yards north of the equator, there would be zero effect. This is what I was meaning in my first post Fact: Projectiles fired in the Northern Hemisphere will always appear to drift right regardless of direction of fire and left in the Southern Hemisphere. My creedmoor like other have said at most HUNTING DISTANCES will not drift much if any at all. But at those target shots PAST 1300 oh ya. Share this post Link to post Share on other sites
308Nut Report post Posted November 17, 2015 Will hunt. You had it right. My statement was geared towards other statements by others. 1 Share this post Link to post Share on other sites
WampusCat Report post Posted November 17, 2015 Those are similar numbers to what I see as well. At 308 velocities we are talking 3" at a 1,000yds and less when a faster chamber/projectile is used as the time of flight is reduced. What I really wanted to make clear to folks (without sounding like I was arguing) is that there are much more important things to correct for (wind and spin) 1 Share this post Link to post Share on other sites
WampusCat Report post Posted November 17, 2015 My creedmoor like other have said at most HUNTING DISTANCES will not drift much if any at all. But at those target shots PAST 1300 oh ya. Your Creedmoor will be less than 308's as your velocity is faster and your likely higher BC will shed that velocity slower. We are talking maybe one click on a 1/4 MOA turret. 1 Share this post Link to post Share on other sites
308Nut Report post Posted November 17, 2015 For arguments sake (respectfully) my 6.5 X 284 mathematically has only slightly less Coriolis at a grand. To the tune of 1/2" less. The reason I see around 3 inches with my 308 and 6.5 and 300 win mag is because I am at the 61st parallel. That said, I will adjust for 1-1/2, 3 or 15". I wish to eliminate as many variables as possible. Wind, spin, Coriolis...all of it. Share this post Link to post Share on other sites
308Nut Report post Posted November 17, 2015 What velocity are you getting with you creed and with what bullet? Share this post Link to post Share on other sites
WampusCat Report post Posted November 17, 2015 That said, I will adjust for 1-1/2, 3 or 15". I wish to eliminate as many variables as possible. Wind, spin, Coriolis...all of it. AGREED 100% Share this post Link to post Share on other sites
