Polishing expander down .001

[WEL]

I have a Lee sizing die( I know I know but it’s an odd ball caliber and all I could find) in 350 Rem mag giving insufficient neck tension. The ball diameter is .358. What size grit is best for taking it down a .001- .0015? I had purchased a Redding die a while back went to use it and the expander ball is .336. Pretty sure thats not going to work lol. Must have got a .338 by mistake.

 

[BlackGrouper]

I use 320 emory cloth.

 

[paperpuncher]

Chuck it in a drill and polish it down 320 would be a good start even 220 if it is slow going and you want to speed things up. Leave it a tad big and go to finer grits to get a nice polish and hit your number

 

[Clancy]

Only ever done one and I think I used 400, should have used 320.

The drill worked fine for turning it

 

[WEL]

Just used some 400. Seems to have done the trick. Hardest part was getting that lee spindle back in the die. It doesnt go in from the top like every other I’ve seen and you have to drive the pin back in the nut with it slipped through the die pita. Thanks.

 

[K22]

I done a bunch of them since I control neck tension with expander balls not bushing dies. I have four expander ball assemblies size in .001" increments for each caliber I load.

I used 220 grit paper with assembly chucked into drill. Make sure the set up is level. Go slow and check frequently with a quality micrometer. The end result should produce a ball with a glass like finish which greatly aids in passing through the neck of the case.

I also brush out the necks with a nylon brush chucked in a low RPM speed drill to remove any build up carbon residue before sizing. This also aids in the ball passing through the neck and not stretching it.

 

[asquared19]

only done one, and it was with 400 grit in a drill press. worked great and checked often with a micrometer as suggested. like most things, I overthought it, but was happy when I just dove in and got it done.