Picked up some nightforce ultralight 4 screw rings. I noticed the top cap has a slightly smaller radius than the base. See pic. It’s like this on both rings so I’m just thinking this is by design. Is this normal?
I've only purchased one set of NF rings and one NF rail. The fit and finish were atrocious. I returned them to sportsman's warehouse and never looked at another set since. Nice scopes but it's clear they have or had rebranded junk for mounting hardware.
They're machined correctly, they aren't zero gap rings. Place them loosely on a scope or boring bar and you'll see they are made that way. I've mounted literally multiple hundreds of scopes, NF rings are some of my favorites. Never an issue. Just mounted some Seekins on a Havak, those were nice as well.
Leupold Backcountry's used to be decent, now with the t-27 head, they're garbage. I was in favor of the change from the 1/2" nut of the previous rings, until I mounted a few sets. They won't stay parallel to each other and end up binding the tube.
I have a set of both the 4-screw and 6-screw NF's and they are both the same like yours. If you pull on the top half of the ring so there is a small gap between the two halves (like if you had them mounted on a scope) then you have a 30mm circle. The way you are looking at them now, they are approx 29mm measuring vertically with the two halves touching.. Hope this makes sense.