When mounting a scope for someone what is the best way to determine the position for eye relief. I am mounting a scope for a friend and he will not be here for a week or so.
Is there a rule of thumb.

Depends on the dimensions of the shooter and the eye relief of the scope.A large shooter will be farward on the stock and requires the scope mounted more forward.If you and the shooter are the same size you could be close setting it up for you.

Well I'm a large lump of a fella, and I can never get scopes back far enough. Usually resort to cutting an inch of the stock. I must have a short neck.
But if we are talking about a kicker, best a bit too far forward for a start, most people can crawl up a stock if they have to.
John L.

The best way I've found to determine the best position for the scope is to have the person who is going to use the rifle hold it up in a comfortable shooting position. I then put a strip of masking tape on the stock right under there aiming eye for a reference point. I then measure and put another strip of tape 3" in front of the first piece. I then mount the scope with the eyepiece even with the forward reference point on the stock. You can fine tune from there. Remember that if it is a varible scope to set it at it's mid level to high power setting when checking for eye relief.

This works for me. Good luck and good shooting.

When I mount my scopes I try to center the turrets on the ejection port (astetics) then you can adjust from there. Trial and error work best for me. Every time I have someone else mount my scope they always seem to leave ringmarks and scratches. I take my time and make sure my rings are straight and tight before I tighten down the rings.

Mount the scope, loosen the screws, if it is a variable turn it to the highest power. Then mount the rifle to your shoulder in a shooting position and position the scope forward or back so the image just fills the eyepiece of the scope and tighten it up.

Like Chic does it, been working for years..