I'm getting ready to use some Lee Collet dies for the first time...if I recall from previous threads there is some prep/polishing procedure some of you do before you start using them?

Could you refresh my memory/give me some instructions?

thanks

Roger

The polishing is done on the mandrel where the neck is squeezed down to make the necks slightly smaller so they grab the bullet tighter. This is done only if the neck does not expand at least .001 when the bullet is inserted. You can also buy separate mandrels from Lee for I think $8. You must specify how much smaller you want them. What you do yourself is chuck the decapping pin in your drill and then LIGHTLY apply some emery cloth to polish it down no more than .001. It comes off real fast so only do a little at a time. Only do this if the bullet is not held tight enough. You can also use the factory crimp die. This in my opinion works better.

I also like to check the slits in the collet to make sure they are clear of any machining debris and take some folded sandpaper and clean the slits ....I also use some oiled fine 400-600 paper on the outside of the collet cone to make sure the outside surface doesn't have any "high" spots and feel inside the die for any rough spots where the collet is forced aganist the inside of the die and aganist the case neck and mandrel.....Don't over do the polish ...just remove any felt rough spots and check to see if a case neck shows any scratchs when you size a fresh case......I use a good high pressure lube such as Pro-tec or bolt lube on the inside of the die and outside of the collet to make sure the collet can move freely aganist the die......hth..good luck and good shooting-loading!!