Is it supposed to be sticking out a little?
In actual reply, I don't believe that it is a cause for concern. I personally tighten that screw until it touches the mainspring and stop. Uberti mainsprings generally don't need
more tension. When you screw it in, as it tightens against the mainspring, it will get harder to turn as it presses on the spring. I imagine that you
could get it to screw in flush if you turn hard enough, but it's only going to serve to make your action harder to cycle.
Now, Coffinmaker and others here are much more familiar with this and possibly will step in and correct me, but this is my take on it (not having seen your gun). Hopefully that helps.
CC Griff