Rifle Scopes Diopter/eye box questions?

[mustang-cars]

I recently purchased a new Vortex Razor Gen ii 4.5-27x56. This is my first FFP scope. I've always used SFP Leupold scopes. I followed the sticky in this section for setting up the diopter. My problem is that when I'm looking through the scope, especially under higher magnification, it feels as though my eye is straining or there's something over my eye. Its also very picky when I move my head left to right. I did get my stock adjusted for a better cheek weld with the scope and that helped slightly but that was only in one position. When I'm in that field at a match there will be variables to that obviously. I have set the diopter according to the sticky several times and it hasn't changed. Honestly the cheap Leupold was easier for me to get behind. I know the Razor is a much better scope so there's something wrong with what I'm doing or maybe something wrong with the scope? Maybe its an issue of FFP vs. SFP? any input would be appreciated.

 

[JayOpticspecialist]

when you turn up the power on any scope, your exit pupil gets smaller, so it gets a little harder to get behind the scope in a perfectly. you can either reduce power a little or practice and get used to getting you eye into the exit pupil. you might try adjusting your stock if you have an adjustable stock, or adjusting the scope if you don't. turn the power up and make sure when you get into shooting position, you can see perfectly through the scope.

 

[V-Ref]

Take a piece of paper (envelope, notebook, etc) stand beside your rifle, and put it behind your eyepiece. Watch the exit pupil change in size and intensity as you vary both the magnification on the scope, and the "eye relief" of your sheet of paper. The amount of fore/aft/left/right/up/down of an intense and full sized eye pupil will help you perceive what's referred to as the "eye box" ...or how forgiving a optic is to eye position.

Where the reticle is placed (first or second focal plane) shouldn't have much to do with this scope attribute as long as there isn't a malfunction.