Any suggestions how I can mill 1/4" 12L14 rod, vertically in the vice, to leave a cylinder 0.06 diameter and 0.22 tall?

I've tried: One pass, multiple passes to full depth sneaking up on the diameter and multiple passes at final diameter but working down. Whatever, I get a pyramid about 0.05 to 0.04 at the top!

Not really looking forward to using the lathe because what has to be milled below the cylinder requires precise centering and there are a couple of dozen to do.

would I be any better using 4140? Using 1/8 end mill but not sure this is an issue. 1"/min feed at 1900 rpm on a Taig mill

Thanks.