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Re: Zero shift?
Posted: Sat May 22, 2010 10:36 am
by Jerry G
Come on you guys cut me some slack, I wasn't the only one. It was nice and warm around the stove.
Re: Zero shift?
Posted: Sat May 22, 2010 6:03 pm
by Innocent
Jerry, think man, think...you were blocked in next to the stove by all the others trying to get in for the group hug, just to stay warm, and couldn't get out to your relay.
Innocent
Re: Zero shift?
Posted: Sun May 23, 2010 5:16 pm
by Jerry G
Mary, I guess you saw how they had me blocked.
Re: Zero shift?
Posted: Sun May 23, 2010 5:42 pm
by BCloninger
A whole new meaning for "Warming shed".

Re: Zero shift?
Posted: Sun May 23, 2010 6:10 pm
by atomicbrh
The biggest mistake Joel and I make is not trusting our hold early on in a match and on the first animal when we change distances. We hesitate to click or hold based off of our very first shot. Then we get 2 or 3 animals behind.
Jerry Tureau mentioned earlier by Innocent never doubts his hold and thus never hesitates to click in any direction at any time. Jerry has so many scope setting stickers on his rifle it would take awhile to read them all. I keep telling Joel we must never hesitate to click and always think that our hold is good. Never hesitate to click at any time. This game is all about mental strength. If you believe that you can hold a tight group you will hold a tighter group no matter what your classification is.
I think the Turkey's head exists to test your zero during practice. It is just there during the match to distract you.
Bobby R. Huddleston
Re: Zero shift?
Posted: Mon May 24, 2010 8:33 am
by Jerry G
I'm not sure where the line is between good hold and knowing where you broke the shot. If you know where the dot was when the shot launched, you can make corrections assuming you have a good spotter. Not everyone is a good spotter and a bad spotter can do more harm than good. You can live with a call on one side of the turkey leg or the other but on one end of the ram or the other is not acceptable. I guess if you have a real good hold and follow-thru you should be able to see your hit but the question still remains is if it registers on your mind. Both you and the spotter have to be there 100% and not listening to a good hunting story.
Re: Zero shift?
Posted: Tue May 25, 2010 1:32 pm
by ShooterP14
Jerry G wrote: Both you and the spotter have to be there 100% and not listening to a good hunting story.
Absolutly! Which brings me to my bigest peeve - People holding loud conversations behind the firing line. Please keep it down or move it away from the firing line.

Re: Zero shift?
Posted: Sun May 30, 2010 2:38 pm
by yankee
Sorry I am a bit late in getting into this conversation. 20 years ago I used to figure to take a minute out over 100 degrees and add a minute below 30 from a normal zero temp of lets say 75. There are very few places you will shoot that the temp will vary more that 25 to 30 degrees during the day. If it does change more just adapt to it. Not counting wind the sunlight -- mirage -- will cause the most change. There are a whole bunch of factors involved including. Height of target above the ground, contour of ground befor the target. Color of the ground and so on. In other words a target 6 inches off the ground will be more affected than an target 4 feet off the ground at a certain time of day with the ground heating and the resulting mirage. All this fancy talk and articles will give you something to think about on cold winter nights. But it is summer now and what you need to do is go by a case of ammo and get out and practice. Then in July go get another case and practice some more. And shoot matches everywhere and get used to different places and how things are set up and what it does to your bullet. Then in August get another case and have some more fun.
Don't worry about the magnetic pull of the poles or if the world turns faster the closer you get to the equator.
Practice
Re: Zero shift?
Posted: Mon Jun 14, 2010 9:07 pm
by RBriscoe
yankee wrote:<snip>a target 6 inches off the ground will be more affected than an target 4 feet off the ground at a certain time of day with the ground heating and the resulting mirage. <snip>
Indeed, there are several ranges I have shot at where the lower of two stacked banks has a very noticeable difference in the "lift" from mirage or whatever.
Jerry Tureau has a chart he carries that he spent a day at the range generating which shows the pattern of bullet impact change (vertically and horizontally) over time as the sun changes position. He swears by it. I am not sure whether anyone else has taken the time to try to duplicate the result, but lighting conditions do make changes.
The spotter is your guide.
Re: Zero shift?
Posted: Tue Jun 15, 2010 7:43 am
by Jerry G
Mary, the test I did was at 100m. I should try it with the HP at 500m.
Re: Zero shift?
Posted: Tue Jun 15, 2010 8:10 am
by Dee
Here is Jerry Tureau's Ram shot mapping experiment. I plan to try it myself one day at the house when I get a free day I'll be around all day. I wish he had recorded the temperature/humidity and barometric pressure as well. Not sure when he shot this but from the times he shot I would assume it was summer time. As such there was probably a 20-30 degree temperature increase from morning to afternoon.
Dee
Re: Zero shift?
Posted: Tue Jun 15, 2010 12:19 pm
by RBriscoe
Dee,
Please do post back if you try to duplicate Jerry's experiment. Aside from the weather factors, it would be interesting to note the direction of fire at the range. I suspect that the time of year (sun position north and south) as well as time of day may be a variable, but I certainly do not know that as a fact.
Cheers,
Rick
Re: Zero shift?
Posted: Tue Jun 15, 2010 10:50 pm
by Borg
Rick Brisco, formerly of Austin?
Re: Zero shift?
Posted: Wed Jun 16, 2010 3:34 am
by RBriscoe
Borg wrote:Rick Brisco, formerly of Austin?
Yep.
Re: Zero shift?
Posted: Wed Jun 16, 2010 7:50 am
by Jerry G
The pattern on the ram kind of matches what I observed setting up a survey instrument on a target at 100m. From 8am till noon there was a 3 min shift of the immage.