probably the same way i machined my HK11's gas tube to within .0003" of actual diameter, WET SANDING!! lol
150 grit sand paper with water at 2000RPM can get stuff REAL goddamn shiny.
I'm just saying the downsides are in your tolerances, jacob chucks slip; common unavoidable fact, and your tool height is prone to change during plunge cutting. Not saying you cant do a good job with a drill chuck, it's just not a collet. So 4 months eh? learning by yourself? excellent job!

I suggest buying a machinist's handbook if you don't already have one, it's pretty well everything you need to know about machining, feedrates, propper RPMs, machinability and cutting speeds of different metals. The college course primarily teaches safety.