Thread: Calculating front sight height ? ( maths heavy )

Bigger brains than mine required for this one

I have just restored a Sharps 1859 Civil War Carbine
It still had the original carbine rear sight ( which is a very challenging POS )
I installed a circe 1873 front sight from another rifle
The rifle has passed proof and shoots an OK group considering the POS rear sight

But it is grouping 150mm above where I would like it to be

So here are the numbers

Range 25 meters

Group wants to shift Down 150 mm

Sight Radius is 530 mm

How do I calculate accurately how much to build up the front sight blade to lower the groups point of impact by the required 150mm

This will be a good formula to have on file because many of the old military and sporting carbines tent to shoot very high anyway

Cheers