massive reconfiguration time again.

I went with the .042 and they do have a .045 and .047... You know where I'm going next..
Here's something.. squirters show 2 new screws that come with them but they don't. The screws have a hole in them as well and I wonder if this has anything to do with how much flows through them and if the screw that fits the squirter is needed?..