I have a shell holder for my 300 WSM that is too "high". It needs about .015 ground of it.(won't push the shell into the die far enough.)

I tried in the lathe, but it is too hard.

Can anyone grind this down for me?

Do it on your bench grinder/belt sander.
The top surface does NOT need to be flat, and you do NOT need to ram your shellholder into the bottom of the die.

Terry, I have faced shell holders in a lathe using a carbide bit. Were you using HSS?

Tool post grinder in the lathe.

Be sure to "Flag" the shellholder after grinding, so you do not get it mixed up with others, otherwise, excessive headspace will bite someone.

Some shellholders are harder than necessary, guess the makers do not want the average mortal to fool around with them. Many of my old RCBS holders are not heat treated, but some of the new ones will dull carbide.

I tried carbide, and all it did was smooth up the surface.

I'll try the other methods too.