Maybe it is my old eyes ( probably ) but it seems that years ago, it was a piece of cake to get the cross hair nice and sharp. I have an OLD Weaver K4 that is just as bright and sharp as the day I got it.
Beginning with an old Redfield 3-9 Widefield, I was never able to get that cross hair the way I wanted it. I had another 6-18 that was just as bad if not worse.
I have a new reissue Weaver K4 and it has a duplex instead of the old cross hair and you can get that one pretty sharp.
The NightForce is a nice scope but the cross hair never seems just right. It is close but when I start to focus it, it seems as though the adjustments are TOO fine and you can't find that "sweet" spot from coming from infinity to "in focus" and driving through to be out of focus. Normally, on the older scopes, I would go from out of focus to in focus and then to out of focus and reverse direction to get the "right" spot.
Even years ago when I was working, K and E usually had pretty crisp and black crosshairs. There were some Brunson alignment telescopes that were very good and others, all the same model, were not.
Without a clear and black cross hair to get your initial line of sight, it was difficult to set the line of sight and if the crosshair was not really clear, a plunge and rotate to measure the centering of the optical axis and mechanical axis was almost impossible.
Have you experienced similar?