4seventy

Some good points. I forgot to mention them but thought they might be relevant especially for the bullet height impact.

When using open sights I use a circle target and hold at the bottom centre of the target. The measurements are from this point on the target.

I used the top of the V line of the rear sights for the top of the front sight. I did realise this might be causing the POI to be too high if the front sight is designed to be held as low as the V allows.

A question with these older doubles - Is the front sight normally meant to be positioned at the bottom of the rear sight V, or at the top line of the V? Or does it change from rifle to rifle and maker to maker?

I am not in the least worried at the moment. Firstly I decided to put my experiences on the forum so they are recorded and can be used by other 'newbies' to the world of doubles. Secondly the regulating load at these in terms of horizontal disbursement is not far off with this load already tried. Indeed it may just be the sighting arrangement I used as 4seventy has mentioned.

Going to make up another 4 rounds of 105 grains and shoot them out to 100 yards plus another 4 rounds of 107 grains and see how they go.

The rifle is not hard to open in the least re the primers. I will keep going with the Federal magnums unless I have some CCI's on hand (?) until I get hold of some. I assume you are refering to a CCI large rifle magnum primer?

Another question. If the main standing sight is set for 100 yards does this mean the rifle is meant to regulate at 100 yards when set up by the maker ?

500grains - I don't need the sight modification formula yet by a long way. Will telephone if the loads and different sighting arrangements don't work.

I am keeping track of individual chronograph readings.

Today would be a perfect day, completely calm and warm but I am being dragged off to do some Christmas shopping