I saw this in the "GUNS & AMMO" July issue... And tried it with a few modifications.
Using a kitchen island or kitchen - dining room table. (This is assuming your right eye dominant)
Tape a yardstick along the left long edge of the table.
Place a scope next to & up against the yardstick...You want the eye piece of the scope next to the base of the yardstick.
Kneel or crouch down until your right eye is up to the edge of the table looking through the eye piece of the scope.
Slowly slide the scope forward along the yard stick until you have a full circle of light (Mark this spot on the yard stick)
Repeat, keep slowly sliding the scope until you get a full circle of light, keep sliding slowly until the you lose the full circle of light.
(Mark this spot on the yardstick). Do this several times with each scope.
Now you'll know what your personal eye relief is with that scope....(I was trying to decide what scope to put on one of my Hawkens with out the hammer getting in the way !
Here are the #'s I came with with 4 different scopes....This is the eye opening part !
All scopes set on the lowest power setting.
The 1st # is at how many inches I got a full circle of light and the second # is at how many inches I lost the full circle of light.
"Total adjustment range" is how many inches play you have to slide the scope back and forth in the mounts.
#1 Simmons 44mag 3-9x44....2 3/4" to 3 1/2" Total adjustment range 3/4 of an inch
(I've always wanted one of these scopes and just got one)
#2 Basic BSA 3-9x40...3" to 4" Total adjustment range 1"
$50 Bass Pro Special (2003 model...still in box)
#3 Barska 3-10X50....3" to 5" Total adjustment range 2"
Pro hunter w/ Illuminated Recticle
#4 Simmons Blazer 3-9X40 2" to 9" TOTAL ADJUSTMENT RANGE 7" !!!!
(Brand new 2006 model direct from Simmons via their warranty replacement program)
Note...
I taped the yardstick to the table and kept the scope on the inside of it as I slid it back and forth to keep the scope from falling off the table !
It's easier to get your eye up to the edge of the table If you have the right side of your nose up against the side of the table as your sighting the scope....( A Picture would be a big help here but its pretty easy to figure out)
If you try this its at your own risk (some how hurting your eye or dropping your scope).
I found it pretty educational !
Eric