The effects of changing sunlight.

[Terry]

I recently competed in the NBRSA Nationals. Changes in the sunlight produced large changes in the point of impact vertically at 600 and 1,000 yards.
The changes in sunlight were very subtle.

What do experienced match contenders do to combat this occurrence?

Please experienced match contenders only respond.

 

[dkhunt14]

Brighter is higher and darker is lower. I have seen 6 inch changes between sun in or out at 1000 yards. Usually it is around 4 inches worth. Tom is right, you need the guns to track so you don't chase a light change. The problem with the changes is unless it is from full light to dark I don't see it because I am putting in a shell and not looking through the scope when the changes occur. Matt

 

[stool]

iron sight shooters..... light up sights up
not sure how that applies to scope shooters , but it does affect point of aim/impact

 

[DonnyJ]

iron sight shooters..... light up sights up
not sure how that applies to scope shooters , but it does affect point of aim/impact

Plus 1..

 

[Alex Wheeler]

If you have a day where there is moving cloud cover and you know you will have a change of light you need to be aware of the clouds and start your group when you have the widest window. I personally dont like to hold off. If I couldnt finish my group in one condition I would wait until it came back or trust the tracking of the gun if that condition wouldnt come back. But generally I'll wait for a cloud and try to get all 10 off before it leaves. Just because they tell you that you can shoot doesnt mean you have to. But if your gun tracks like Toms you don't even look in the scope you just let the gun do its thing.

 

[mgva]

Terry,
Wish you would have tried one of the scope filters you have.The amber filter that you used before or yellow filter may have helped.

 

[Chuckhunter]

Terry, I'm not and experiened long range shooter, I'm still working on that. I can tell you however from past experiences at short range BR matches, that the saying was sun up, shot up, sun down shot down. In short range matches, we had the luxory of returning to the sighter, to see how much the poi was shifting. I would normally shoot either a well lit sunny target or a darkened target from cloud cover depending on which condition was more prevelant. Until I get to a 1000yds and actually compete there, I'll be keeping a close eye on this thread and listening to what the pro's say. Thanks for posting this excellant question.

 

[Terry]

Terry,
Wish you would have tried one of the scope filters you have.The amber filter that you used before or yellow filter may have helped.

I was using a new scope that they did not fit. I'll fix that.

 

[Immike]

When the sun comes out from behind the clouds then the mirage will move (what you see ) in the scope. This movement takes several seconds to a minute to settle down. The target moves Up and down wind. When the sun goes into the clouds then it will sink back down. For benchrest it is better to shoot one or the other if possible and be aware of this. We are aiming at a image transferred to us by light. There is some advantage to being up on a bench since this is much worse the closer you are to the ground (the source) and more so with higher moisture. A high spot in the field can add to this movement.