Before I jump to conclusions, when you say "eye relief" are you talking about the distance from your eye to the rear of the scope when you see the full sight picture thru the scope? If so then...I have a Simmons Prohunter 6-18x40 on my 17HM2 and they make a good combo but I'm getting a little annoyed with the eye relief, seems like it's more like 8" then 3". Could it possibly be I need to reset up the scope and it'll be more normal or is it just the way those Simmons are? I use a Dednutz mount so I can only go so far forward and I'm to that point where I either fix it, replace the mount to get forward or replace scope. What say thee
Something is wrong with the scope. I have a couple of Simmons (not your model) and the eye relief is around 3". The specs for your scope say 3.9" of eye relief so there is something amiss if your eye has to be 8" from the rear of the scope in order to get a good, full view thru the scope.