the runout on my nm145 spindle is unmeasurable.
the runout on my COLLETS, well thats a different subject
so make sure you figure out what the actual source of runout is or youll be chasing your tail.
cheap r8 collets and ER chucks/collets can be terrible and often have burrs. also any dirt on the collet or taper can throw out a long tool by a large amount.