Lapping out a sizer die
- Thread starter waco
- Start date
I used 400 wet dry paper and some light oil. Wrap the paper around the split rod then roll the die on your leg, back and forth while move the rod in and out of the die. This keeps the polishing even.
Or, if adventurous use the same rid and paper but spin the rod with a cordless drill spun slowly. Go slow, check often.
To check size clean the die well, put in press and size a bullet. Measure bullet with micrometer. When close go to 600 grit for final polish.
If talking a Lee die realize the actual sizing section is quite short.
Or, if adventurous use the same rid and paper but spin the rod with a cordless drill spun slowly. Go slow, check often.
To check size clean the die well, put in press and size a bullet. Measure bullet with micrometer. When close go to 600 grit for final polish.
If talking a Lee die realize the actual sizing section is quite short.
Once you do a few it is less frightening. Having made a bunch on the lathe I now just dive in and go for it.
Always remember you can take more off but it is damn hard to put it back. If you need proof I have a handful of oversized push thru sizers.
Always remember you can take more off but it is damn hard to put it back. If you need proof I have a handful of oversized push thru sizers.
Hawk
Well-Known Member
I use a portable drill and chuck the die in a vice so when the drill is setting on the bench, the wooden dowel is centered in the die.
I use a wooden dowel that is much smaller than the die and let centrifugal force apply the friction. The sandpaper should be a loose fit in the die, or you risk an out of round die.
I agree with Brad, 400 grit wet/dry sandpaper with oil to start and 600-800 sandpaper with oil to finish. The final polishing may take another .0005 off the die, so leave yourself some room to apply the final polish.
Go SLOW and check your progress often by sizing a slug thru the die.
I use a wooden dowel that is much smaller than the die and let centrifugal force apply the friction. The sandpaper should be a loose fit in the die, or you risk an out of round die.
I agree with Brad, 400 grit wet/dry sandpaper with oil to start and 600-800 sandpaper with oil to finish. The final polishing may take another .0005 off the die, so leave yourself some room to apply the final polish.
Go SLOW and check your progress often by sizing a slug thru the die.
I would use the lathe these days. Spin the die with the lathe and hold the split rod by hand. Let's me put taper when I want and smooth the entry hole to eliminate sharp edges.
Lee uses a pretty soft steel in these dies and the actual sizing section is quite short. Polish in that short area and it does go quickly.
Lee uses a pretty soft steel in these dies and the actual sizing section is quite short. Polish in that short area and it does go quickly.
Ian
Notorious member
I use a drill press and drill bit that's about 1/16" smaller than the hole. Tear a 2-3" ribbon of 400 Emery paper, attach to bit with thin painter's edge tape (the super-thin blue stuff), and spiral around the bit. Lube with wd-40, ATF, or water. A thousandth is easy, in fact that's about what gets removed during a "standard procedure" Lee push-through polishing operation. I like to let the die spin slowly as I'm lapping to help keep it round, and bob the die up and down to get a cross-hatch pattern inside.