Hunter02, try an experiment for me.. with your PST at 6x, slide your head back on your stock as far as you can while still maintaining a full sight picture. Once you reach the point where your sight picture starts to 'black out' on the edges, stop (this is the max eye relief). Now, with your head in the same position as stated above, run your scope through the magnification range. You will notice your sight picture start to black out as you increase the zoom. In order to get a full sight picture again at max zoom (24x), you would have to slide your head/eye forward on the stock towards the ocular lense.
As SideCarFlip was implying, this happens with all scopes. You just don't notice on your particular setup since your scope is setup such that your head/eye is in an optimal position (full sight picture throughout the magnification range).
Originally Posted by Hunter02
Yes I am sure, I had the scope in front of me and went through the entire mag range (starting on the lowest) and did not have to move my head what so ever to get the full sight picture. In my mind that is the definition of staying consistent. And look at there specs on there line up for the PST's. They are listed at a consistent 4". Not a range like the Viper's, Diamondbacks, and Crossfire's. If you were referring to the Viper's, you are correct. If you have to move your head closer because you are going up in magnification, you mounted your scope incorrectly. I think first hand experience trumps your scientific explanation. I will agree it is less forgiving at higher end magnification, but the eye relief is not changing.