Silly question, but how do you measure groups when sighting in a rifle? Outside edge to edge? Center to center? Widest shot to widest shot?

Pardon the newbie question but I am curious. Being an engineer, I may have tended to over analyze this.

Ross,

It's center on center.

Mark

With me it depends on what I am trying to find out.

If I am testing different factory or handloads in a particular rifle I measure center to center of only the shots that I felt good about when the rifle went off. I disregard a shot if I flinched or was not on target when the rifle discharged.

If I am deciding which rifle to take on a hunt or safari I shoot a ten or twelve rounds with each from off the sticks and take the rifle that has the smallest outside group.

The usual definition is center to center, however the way it is usually measured is outside to outside and then subtract the bullet diameter.
Peter.

quote:

Originally posted by Peter:
The usual definition is center to center, however the way it is usually measured is outside to outside and then subtract the bullet diameter.
Peter.

What he said.

Sighting in I measure outside to inside--then you dont have to subtract bullet diameter.

SSR

quote:

Originally posted by Cross L:
Sighting in I measure outside to inside--then you dont have to subtract bullet diameter.

SSR

What he said.

Dear Dogcat

In Aussie for target copm's we measure out side to out side and subtract the bullet dia.

This gives you the actual group size no matter what cal rifle is used.

Regards Mark