Lapping seater dies

[tomme boy]

Anyone else have to lap out your seater dies? I have had to do a few of them because they were swaging my boolits down when seating. My newest one is a Lee for the 7.62x54R I also have a RCBS seater for this that is even tighter in the neck. I am going to do the lee as it is cheaper if I mess it up. I am running a 0.314" boolit and if you pull it after seating it is 0.313". I have 0.002" of neck tension so I know it is not that. You can feel it when it seats the boolit.

I have also had to do this to a 9mm that I have to run a 0.359" boolit in.

So how are you guys lapping them out when you have to? I use 600 grit sandpaper spun around a shaft and then oiled and spun with a drill to lap it. Then use 1500 grit to polish it the same way. It takes awhile this way but seems to work for me.

[EDG]

Get a barrel lap for dies that have a straight through open top design.
Get a the blind hole lap for blind or dead end holds. They require a mix of light oil and silicon carbide or other abrasive to make them cut. Complete laps and replacement barrels can be found on eBay for $6 to $12. They are adjustable and allow you to carefully control the hole size.


http://www.moldshoptools.com/catalog/list.php?category_id=103

[petroid]

I have seen it done with sandpaper around a dowel and run through the die. Then roll the die across the bench on a towel or rubber mat while holding the dowel. Seems to do a good job