Gamewarden, they still make a 4-16X50 but its now and F2, ( quit making F1 in 2021) and yes they make ATACR 4-20X50 F1. Ive never played with the 4-20 scopes but interesting. I wonder if the eye relief is better on the ATACR 4-20 vs NXS that was reported as a bit tight. You have one by any chance?
Boomslang, my 4-16X50 F1 ATACR has zero stop but it doesn't have the button that allows you to go below the zero stop like the X42. That is the only scope that offers that feature. ( I'm quoting NF, I'm no expert) The guy at NF gave this explanation and I'll probably butcher it but here goes. Paraphrasing
"The X42 has the button that allows you to go beyond zero stop bc it was made for low profile gas gun purposes (AR10-15 maybe) and if you were laying on your side with port side up, you could use the elevation knob as windage knob while prone on side". We both laughed about it. Just so you know that was some engineers concept of that zero stop.
I usually just set my zero stop a mil past needed in case my load changes and want to rezero without the extra zero stop drama. I like the feel of the taller turret but like the height of the low profile turret so its a mixed bag for me. The low profile turret has a different set of tiny tiny screws that causes me concern but only caused problems once. I can't remember but think I tightened them too tight and stripped them as a result. The regular screws are small enough.
I repeat, I am no expert and understand I am not trying to act as such, just passing on what I would think others might want to further understand as I did. Shout out to NF, they called me back immediately and when I had a follow up question, two people called me back with one right after another. Very impressive company customer service. Monster shout!
PB