FL Die Shaving Neck?


Full Member
Apr 6, 2010
Jamestown, ND
Brand new Lapua brass
Brand new RCBS FL die, cleaned
First time using Imperial wax instead of One Shot

All my previous experience has been with Rem brass, lubed via One Shot, using RCBS X sizer die. There was a lot more resistance with the Lapua brass and regular die than what I've experienced with Rem brass, X die, and One Shot.

Die was initially set up per RCBS instructions. Got to sizing and noticed a "ridge" at the neck/shoulder junction. I could see it, and feel it with my fingernail. I took the die apart, cleaned it, lubed up a few cases with One Shot and got the same results. I then starting playing around with different positions of the die, going in an eight more turn, backing it out quarter turn, etc. Still got same results.

This picture is when I had the die backed out a quarter turn from contacting the shellholder. This moved my "ridge" up onto the neck. Looks like material is being shaved off the neck. You can clearly see the distinct line there.


What is specifically causing this? I didn't notice anything out of the ordinary inside the die when I had it apart for cleaning. I also didn't notice a pile of brass shavings.

Is it mostly cosmetic? Would you proceed to load these cases up as is? My intentions are to FL size this new brass, load up and fire, and start neck sizing thereafter. I will get into the nitty gritty load testing once I have fireformed and neck sized brass.


milo 2.0

Re: FL Die Shaving Neck?

It is from the case mouth, you might deburr and chamfer them to get a smoother surface. And you need to get the brass out of your die, it will come down on the sides of your case if you don't, and make s mess of your die.
It can't do your brass any good either.
Lube your expander ball also, it is pulling brass pieces out on the upstroke, or take it out and do it in two steps, outside, then inside.
Unless they are way out of round, I would just chamfer and shoot them.


Full Member
Jan 6, 2009
Ringgold, Georgia
Re: FL Die Shaving Neck?

May be a long shot but have you got the expander ball to high? It appears it's shaving down but maybe it's actually on up stroke and expander ball is inside neck while die is still tight on the neck. Not sure that's even close to right but would be easy to check by just taking expander out and sizing a case without it.

Side note, using Imperial I run the fingers I used to lube outside of case across the case mouth to make sure I'm getting lube on expander and inside case necks.

When setting up your die, set it so you're getting proper shoulder set back. Setting up based on shell holder can end up with shoulder being set back to much or to little. Neither is good.