This is how to alter the parallax/focus on a non-AO scope. The writing is a bit stilted, but it explains the method OK.
Scopes without PA adjustment are generally supplied by the manufacturers with the
parallax set to 100 yards (50 yards in the case of some rim fire scopes). This is too far for
typical 25m gallery use.
Fortunately for us most scopes are easy to re-parallax. Here’s how to do it:-
First set out a target at the desired parallax range. Then remove the end ring on the object
lens of the scope. Most will loosen with a firm hand grip; you may have to use a strap
tool to loosen the very tight ones.
After removing the end ring you will find a threaded inner tube carrying the end lens of the scope.
Some can be rotated with finger pressure, others will need a flat blade across the two slots in the
threaded tube to turn it. I find a steel rule ideal. Now unscrew the threaded lens carrier (moving the lens further out)
to reduce the parallax distance. Unscrew slowly till the target you previously laid out comes into sharp focus.
Fortunately for us the point of minimum parallax error is also coincident with the sharpest focus at that range.
Now the tricky bit, you have to replace and tighten the scope end ring without disturbing
the position of the now adjusted inner threaded lens carrier. It may be necessary to use
something to locate into one or both of the slots in the inner threaded part to stop it
turning as you tighten the end ring. Be careful! One slip and you could damage the end
lens permanently if you use a metal tool to stop the lens carrier rotating.
Once the end ring is tight again, that’s it, you have re-parallaxed your scope.
You can use the same method on AO scopes that won't focus down to 25m once you've discovered how to remove the objective cap. It will screw up the distances on the 'parallax' ring, but you can't have everything!
One of the clearest scopes I've ever used is a Nikon Pro Staff EFR 3-9x40AO, crystal clear glass and parallax adjustable down to 10yds. So nice i bought one for my gallary rifle after another club member was kind enough to let me try his.
This is how to alter the parallax/focus on a non-AO scope. The writing is a bit stilted, but it explains the method OK.
Scopes without PA adjustment are generally supplied by the manufacturers with the
parallax set to 100 yards (50 yards in the case of some rim fire scopes). This is too far for
typical 25m gallery use.
Fortunately for us most scopes are easy to re-parallax. Here’s how to do it:-
First set out a target at the desired parallax range. Then remove the end ring on the object
lens of the scope. Most will loosen with a firm hand grip; you may have to use a strap
tool to loosen the very tight ones.
After removing the end ring you will find a threaded inner tube carrying the end lens of the scope.
Some can be rotated with finger pressure, others will need a flat blade across the two slots in the
threaded tube to turn it. I find a steel rule ideal. Now unscrew the threaded lens carrier (moving the lens further out)
to reduce the parallax distance. Unscrew slowly till the target you previously laid out comes into sharp focus.
Fortunately for us the point of minimum parallax error is also coincident with the sharpest focus at that range.
Now the tricky bit, you have to replace and tighten the scope end ring without disturbing
the position of the now adjusted inner threaded lens carrier. It may be necessary to use
something to locate into one or both of the slots in the inner threaded part to stop it
turning as you tighten the end ring. Be careful! One slip and you could damage the end
lens permanently if you use a metal tool to stop the lens carrier rotating.
Once the end ring is tight again, that’s it, you have re-parallaxed your scope.
You can use the same method on AO scopes that won't focus down to 25m once you've discovered how to remove the objective cap. It will screw up the distances on the 'parallax' ring, but you can't have everything!
