How to Calculate Scope Height

[@paulbotha5594]

Very useful video, thanks Wynand. I always used to just eyeball it with a Vernier from the centre of the tube near the turrets to the centre of the barrel, which is fine shooting silhouettes out to 40 meters, but for 50 meters plus accuracy, this method is waay better.

[@vicentemaricosta9109]

Nice video! Step 3 in the images at the end of the video is not correct. The distance between the barrel and the scope should not be divided by 2. The correct measurements for the height of the scope in that case would be 25mm (scope) + 12.5mm (barrel) + 10mm (gap) = 47.5mm but it can be rounded to 4.7 or 4.8cm.

[@markthompson4859]

Lekker ! At last! Shot for this!

[@gbone7581]

77.62 mm = 7.762 cm rounded = 7.77 or to one decimal place 7.8cm.

[@badgerairsport]

Thanks!

[@JDG506]

That is perfect if the scope is mounted parallel to the barrel. If the scope is shimmed, or mounted on a 20 or 30 MOA slanted rail, or on adjustable mounts, the front of the scope will be lower than the rear of the scope. The author of the ballistics app said the measurement should then rather be done from the centre of the windage knob to the centre of the barrel, to get it as close as possible to the crosshair height.

[@badgerairsport]

Thanks so much for this Johan! An integrated POE brings the objective lens closer to the barrel, because of the angle. Therefore the featured calculation should be more accurate than trying to measure the turrets, normally over the working parts of the rifle, no?

[@stephenbroadhurst7653]

I think this might help with your problem, when a 20 MOA rail is fitted to a rifle as you say it does angle the front of the scope downwards so measuring the height at the centre of the scope would be more accurate. But this is not the most accurate method, imagine the scope is angled downwards in relation to the path of the projectile, but while the scope is angle downwards you’re line of sight is not because you are still looking at the target. This is achieved by adjusting the reticle via the turret which raises the front of the erector tube which is inside the main scope tube at the (first focal point) but this point is not fixed and moves with turret rotation. It is better to measure the scope height at the (second focal point) because this is fixed and never moves up and down and is where the erector tube hinges from. On a modern scope this point is just under the zoom ring at the rear of the scope and this is where you should measure the height with a canted rail. I know this seems like a long response but if you search for a cut away view of a scope this might help.