I cut the nipple end off with a cutoff blade, square, drilled the 2 ends out after, then fitted a long 1/4-20 carriage bolt down the centre and chucked that up in my hand drill, and began the polishing. I started at 320, then 400, finishing up at 600, then went for the metal polishing compound that made it really bright and shiny. But I reasoned that being steel, it would likely then begin to pit or worse, so either paint or blue was in order. I went for the blue and it took a few coats but came out nice. Next semester i should have access to the student lathes again, and I'm planning to make a few muzzle brake/weights, in aluminum and brass. I also have some Mg alloy stock that would make some very light muzzle brakes, but I have no idea what it would do long term, since it would be a sacrificial anode if there is contact with the steel barrel (which has contact with all the metal parts of the gun) then perhaps the whole action from trigger to muzzle would be protected. I have never seen or heard of a sacrificial anode deliberately installed on a gun but I don't see why the concept wouldn't work. Aluminum is used pretty extensively (which is why I find the regulators in PCP guns have so much corrosion, where they contact the inside of a steel tube). Brass is commonly used for bling-bling (triggers, bolts, bolt handles) and it is more cathodic than mild steel but because the steel (anode) surface area is so much larger than the brass (cathode), the corrosion rate is very slow. Atmospheric corrosion is much more dominant in that case than galvanic corrosion between brass bling and steel action.
