If it's for a 25.0 bar it may also be a 22.0 quill, which means you're boxed in a corner fork ID is not 22,2mm either .
a small adjustable hand reamer is the right tool, I'd get a section of 1.0 inch tube to test fit, as the reamer is slowly expanded , then the cut will be smooth, and uniform , as soon as the 1" tube fits in you're done
then you will be assured the bar will fit in . when you slide it thru the stem..