Caught in a lie

[susan]

Hello naughty nickos

I'll calm you down if I pick your car keys

[Reader]

The initial “alignment” is obviously along the length of the rifle

That should have no effect on elevation or windage, as the groves used presumably run true to the direction of the barrel. As there would be no reason to move the wheels used for zeroing the sight when detaching and reattaching the sight, why would it need to be zeroed again?

[ngb1066]

That should have no effect on elevation or windage, as the groves used presumably run true to the direction of the barrel. As there would be no reason to move the wheels used for zeroing the sight when detaching and reattaching the sight, why would it need to be zeroed again?

Because it is never possible to attach the sight in exactly the same position and seated as it was before being removed.  Microscopic differences make a material difference.  It is possible to get sophisticted mounts which make a sight virtually self zeroing (i.e. the sight can be removed and refitted without the need for rezeroing).  However, these are unusual and only normally used by big game hunters who need to be able to switch from telescopic sights to open/iron sights and back again very quickly in response to changing circumstances in the field.  The Anschutz rifle at WHF required zeroing whenever the sights were reattached to the rifle.

 

[Nickos]

That should have no effect on elevation or windage, as the groves used presumably run true to the direction of the barrel. As there would be no reason to move the wheels used for zeroing the sight when detaching and reattaching the sight, why would it need to be zeroed again?

Because reseating the sights will have an effect on the precision of aim.

This is a precision exercise (cross hairs aligned to a target at distance) any small deviation from the original setting will have an effect on the accuracy.

Have you a gun shop nearby?

Perhaps popping in and having them show you / explain it would help.

There might be something on the Internet that could help?

I have tried to make it clear, but sadly failed.

NGB could you help with this? - thanks.

(Edit: Thanks ngb our posts crossed)