I have a couple of sizing dies (eg. 7x57) where the part of the stem that sizes the neck on the upstroke is very tight, and even with lube is hard to pull up though the case neck. Is there soemthing I can do myself to fix this eg.chucking in a drill and using emery paper? What grade paper should I use. Any suggestions?
Thanks, Peter.

Two possible solutions.Redding makes a carbide expander for RCBS...I think.
Sounds like your brass may be a bit thick could try turning the necks down.
Jim

If you have RCBS dies, send them along with 5 fired cases to RCBS in Oroville Ca along with a letter explaining your problem. They will rework the dies if there are any problems or might even adjust them to your particular chamber.

It's not likely that the problem is the die....possible, yes, but not likely...

I had this problem years ago and used graphite on the case neck IDs and it solved the problem nicely. Just dip one in five in the graphite and the problem goes away.

Since then I went to a spray lube and spray the cases at about 45 deg angle from above actually allowing some of the spray to get into the case ID and haven't had to use the graphite anymore.

If you want you can polish the expander button with very fine paper (240 grit) to polish it a bit. It's case hardened and you won't remove much at all from the diameter and this might remove any roughness or sharp edges if it has any. But again, it's not likely this is the problem.

Sounds like thick brass as mentioned by another poster. I had the same problem with a RCBS 6.5 Swede die and polished the expander, no metal removed just polished, useing 1000 grit emery. That and a touch of lube made things a lot easier.

The Forester sizers have the expander up high on the stem where the leverage is greater. They draw the ball back out of the necks with conciderably less noticed resistance. The resistance is still there you just don`t feel it as much.
IMO the expander dragging is a big factor in case stretching. The less drag the less growth I seem to notice. Others may find different.

Here's another solution.
I shoot mostly cast bullets and a friend of mine shoots bench rest. We use the same technique for neck expanding. We resize the cases with out the neck expander in the die. The cases are then cleaned, getting rid ofthe lube. Then we run the cases into Lyman's M-die. I run my cases in deeper to get case mouth flare then he does, since he is shooting jacketed bullets.
We both adjust the degree of expansion by polishing down the mandrel diameter to suit our taste.
Nice thing about the M-die is one die body works for all the calibers I reload for.
Jim

Peter, I think that Blacktailer is right. If the expander button is correct, then the actual amount of neck sizing is too great. You are over working the brass. The neck is getting too tight causing the excess upstroke pressure.

Oversizing is a common problem with some dies and you must remember that this can bend necks when pulling the expander out causing bad bullet runout. The die neck needs lapped out. Neck turning the brass can help but most chambers are too large for it. In all standard factory rifles, I only turn the necks enough to make them even. This means the cutter does not touch all the way around and there will be a small area on one side that is not cut.

Thank you gentlemen! It seems that fixing the mandrel is out of the question (for me anyway). And this actually makes perfect sense to me as I also have a 7x57R and the neck tension is nowhere near as great when I size those cases. So, I either neck turn the brass, which I can do but need to buy another mandrel, or have RCBS fix the dies for me. To those who have recommended lubing the neck, I have tried both RCBS case lube and Mica powder, without too much luck. I am reluctant to use too much lube for fear that I won't be able to get it all out, and hence affect the powder in the case, not so much that it won't "work" but rather that it will stick to the lube and not settle properly in the case. I can clean the neck, but not the shoulder. Any thoughts?
Peter.

The ultimate neck lube, and one that won'tattract powder grains/kernels, is the dry moly powder from N.E.C.O. It comes in a little wide mouth jar filled with steel shot. You dip the case in the shot up to the juncture of the neck and shoulder, then twirl once.

I polish my expander balls by chucking them up and running the ball over 400, then 600 grit sand cloth (with Break Free on the cloth). Then I smooth any sharp angles with an Arkansas stone. Finally I put a glob of Simichrome or Flitz polish on a piece of cloth and spin the expander in that until the polish is black, and the expander is shiny.

As noted above, RCBS will also work the die over (to include enlarging the neck) if you send them three fired cases and a note. They are good about working with their customers.

Polish the expander ball by chucking it in a drill and run it on a fine sharpening stone with some oil and I bet you'll notice a difference. It may not completely fix your problem but it's worth a shot, it only takes a few minutes. I done this to all of mine, I've measured a couple of them before and after and have taken about .0005 of the diameter, but they pull through much easier.