enlarging neck bushings

[porthos]

i have several redding neck bushings .332-.337 that i want to open up. these are not the titanium ones; but, a file won't touch them. would like to open up to .341 to .345. i have a lathe and 5-c collets. any suggestions or just make new ones?

 

[Brad]

You can try polishing them but I bet they are harder than hell.
Likely far easier to buy new.

 

[Bill]

I've enlarged a bunch of std dies in the neck area, rcbs are harder than supermans kneecap, I just anneal them before I start, I have never tried to harden back and they show no wear after years of use (I shoot a bunch) it makes them kinda ugly though

Bill

 

[porthos]

i forgot that i made a holder for a dremel tool to use on a smaller lathe. to be used on the carriage. it will eaisly fit in the tool post on my south bend. the depth of the bushings is only .375. so running the dremel in and out with various grinding bits should not be a problem. i also have pin gages to check progress. i'll report back within a couple weeks. (many other projects)

 

[Ian]

Just make new ones out of drill rod and harden them, then temper in an oven at 400F for an hour and leave them in there to cool real slow. Even an annealed alloy bolt should work for donor material if you don't have drill rod or a broken drill shank to anneal and work with. Trying to grind a circular, concentric, cylindrical hole in a hard piece of metal that's difficult to indicate true in the first place is not my idea of the best approach. On the lathe you'd finish the thing completely in one chucking operation and then part it off, deburr it, and heat treat.

 

[porthos]

if i make new bushings; how would i finish them as far as "grit" for final finish? i have expanding reamers to get me close?

 

[Brad]

I would go to 6-800 at a minimum. A final polish with something like Flitz wouldn’t hurt either.

 

[Ian]

My RCBS bushings shine like a mirror. I'd go at leat 1K if not 2K before heat treating and then polish the scale off with an old bore swab, drill, and some rouge.

 

[Bill]

Smoother the better, don't need sticky

Bill