A New Trick for an Old Dog

Greetings All,
A friend has a rifle with one of the Swarovski scopes with the fancy dots for setting range. He has test shot it at 200, 300 and 400 metres. and asked me to set the scope up for him. The dot turrets had been set up for an earlier load, I had a couple of goes at verifying the trajectory and the adjustments needed by calculation but was getting nowhere. Hint anybody that claims they are as mentally sharp at 75 as they were at 30 clearly has a defective memory. After a little while the light went on. I had the chronographed velocity from my 35P and the BC for the projectile so dialled up the Hornady Ballistic Tool and fiddled with the zero distance until the 200 metre drop matched what my friend had measured. Next the trajectory for 300 and 400 metres from the table were adjusted for the current drops dialled into the scope. This matched pretty much dead on with the measured point of impact. Make the adjustments and job done
There was little point in me testing the results as he will do that. He shoots mostly prone with a bipod and no doubt holds the rifle differently so he can do the final testing and I can make any final adjustments needed.
Regards Grandpamac.

Don't worry bud,all these flash pakeha gears aren't easy to get the head around.

Sounds like you've worked it out pretty well GPM. Any dailable scope should be able to be calibrated in some way that works for the shooter. May not be what the marks say but a basic spreadsheet should give consistent results.

@grandpamac , an interesting conumdrum made complex by yippy tekncrats to make life difficult for us mature old bods. Years ago I gave up the fancy dialling drama when hunting and adipted the following simpler method. This is for hunting, not precision target at long range
I graphed the trajectory lines out to 600 or so for my common calibre and bullet weights. E.g. 308win @ 150grain, 30-06 @165grain, 6.5*55 @140grain etc. Then I held these trajectory graphs over a sunlit window and moved them over each other to set the trajectory curves closely matching each other. It turns out that the point blank zero for each when approximately overlaid allows the observer to notice there is very little difference in correction up or down between common loads and calibres if a zero point of about 250-300 is selected on the scope dial or reticle. It is very easy to come down to 1-200 or up to 350-4,500, especially if the reticle has mil or boone and crockett or other hadh marks in it. I.e. rhe actual corrections required when the zero is around 300 either up or down are far less than if you have zero set at say 100. This for hunting situations but will allow pretty accurate sight corrections in field situations with minimal or no dialling once thr zero is set and trajectories are understood.
I guess one could say its an old trick by another old dog ha ha.

Yes indeed.its almost using the old rule of three minus Kentucky windage lmfao

Yep. In its most basoc form; zero at 300. Aim bottom of chest at 100, bottom third at 200, dead pn centre at 300, top at 400, handspan higher at 500 etc; but doing a trajectory graph curve refines things a bit.