I'll be entirely honest. I've used both 1 and 1-1/8 oz.
It'll depend more on the gun and the shell than anything. Contrary to popular belief, you really need to pattern your gun with a specific shell to see how it's going to do. There really is no generic answer.
I have a couple of 16's and while I haven't used the old noble pump very much (yet because I haven't owned it very long), I can certainly tell you that my old single shot stevens likes 1-1/8" 6 shot loaded around 1300 fps. That's where it shines. It shoots as good as you could expect any shotgun to do and I have had great success with it ranging from turkey and grouse and squirrel and rabbit and ...
But, when you start switching things (wads/brand of shells, velocity, shot size), it can all change very quickly.
So, while I know that my answer probably didn't answer anything, the truth will stand when the world is on fire. You just have to shoot them to see how they're going to do in any particular gun. Having two identical guns sitting side by side are very likely going to shoot differently. That's just how shotguns are.
Last edited by johna1; 09/15/22.
