GT laugh if you will, but I am going to describe what I do. I can get extruded AL sheet at 3mm thickness so I use that on my milling table so that the last pass cuts through the steel and what flash there is limited to where the part shears off. 

Surface grinder: Please sit down here. I rigged up a shower on curtain on an overhear rail around it!! so when a part flies off, it gets stopped by the curtain. Please bear in mind that my normal use is making very small parts to restore old photo equipment for which parts have not been available for a long time. BUT I do occasionally fabricate parts that weigh an ounce or two. Rubber flooring inside the enclosure helps too. 

Here is the evolution of the triggers.  On the right side is a mirror image (reverse set I made for the Ballard) of the original Winchester triggers, on the top is the first go at making a set fit a Hepburn, the bottom set is the latest.  Maybe have a little more time this weekend and do some fitting.