Tech Tip:  When you are ready to install a new rod, do not cut it to length.  Instead, using a suitable source (lighter, match, etc.) slightly mushroom on end of the new rod.

Thread the full length into the sight and pull it snug to the “mushroom” end.  Cut the rod, leaving about 1 mm or less sticking out.  Now mushroom this end as needed.

This way you don’t waste any of the rod.