I'm not sure if shooting the tall target test is an accurate enough way to measure scope error when trying to get below 2%. I'd be interested to know if any members have done several tall target tests on the same scope on different days.
I think unless you are using a benchrest gun capable of shooting in the .1's every time there is too much error. I have done several on the same scope with results from .3% error to 2.4%. Sometimes I can shoot 3 shots in the .1's and others the group will form with .5moa of
Vertical. So you measure your tall target from centre of group to centre but it really depends how your group forms and if its only a .5moa group you can play with the numbers a bit to see how easily your results can change a % or 2.
In my case I could be anywhere from needing no correction factor up to allowing for 2% error which one is true??
I use a tape measure but even then this is not perfect and again if you play with some numbers and your distance is 99.5m or 100.5m instead of 100m your results are rubbish. I measure to the turret some people measure half way between turret and barrel
Adds Some more error in there?? I shoot first thing in the morning when doing this to avoid mirage however there can be slight error in parallax as well that can add to a small % error.
I believe this is better than nothing and will show if you have some serious error like beyond 5% but I'm not convinced that this can produce reliable results when getting below 2%. With shooter and group shape variables as well as measurement error I think the only true way to get the truth would be in laboratory conditions something possibly only scope manufactures have access too.
I think the method of bolting the scope down with some sort of device like some do and running the test without shooting is certainly a better method I don't have the equipment or facility to do this but even then distance measurement and non perfect parallax can still be adding small errors.
I realise the likes of litz in his video doesnt bother correcting scope factor when below 1% but would be interested to see others thoughts on testing the same scope on differnt days whilst shooting and re setting up and re measuring the target each time and shooting the test to see if they have also found this method to have too much noise.
I think unless you are using a benchrest gun capable of shooting in the .1's every time there is too much error. I have done several on the same scope with results from .3% error to 2.4%. Sometimes I can shoot 3 shots in the .1's and others the group will form with .5moa of
Vertical. So you measure your tall target from centre of group to centre but it really depends how your group forms and if its only a .5moa group you can play with the numbers a bit to see how easily your results can change a % or 2.
In my case I could be anywhere from needing no correction factor up to allowing for 2% error which one is true??
I use a tape measure but even then this is not perfect and again if you play with some numbers and your distance is 99.5m or 100.5m instead of 100m your results are rubbish. I measure to the turret some people measure half way between turret and barrel
Adds Some more error in there?? I shoot first thing in the morning when doing this to avoid mirage however there can be slight error in parallax as well that can add to a small % error.
I believe this is better than nothing and will show if you have some serious error like beyond 5% but I'm not convinced that this can produce reliable results when getting below 2%. With shooter and group shape variables as well as measurement error I think the only true way to get the truth would be in laboratory conditions something possibly only scope manufactures have access too.
I think the method of bolting the scope down with some sort of device like some do and running the test without shooting is certainly a better method I don't have the equipment or facility to do this but even then distance measurement and non perfect parallax can still be adding small errors.
I realise the likes of litz in his video doesnt bother correcting scope factor when below 1% but would be interested to see others thoughts on testing the same scope on differnt days whilst shooting and re setting up and re measuring the target each time and shooting the test to see if they have also found this method to have too much noise.
