Thread: Case Sizing Dramas

I am putting little dents in the case necks when FL resizing. From what I read it could be due to a build up of case lube in the sizing die. I have tried soaking the die in white sprits/petrol to clean it out but without success. Also tried changing from a lube pad to spray on lube but no change.

It is now happening in 2 sets of dies; -308 and 7RM, both of which are cheap Lee RGB dies. I have a reasonably light rcbs press which may be part of the problem. The thing I don’t understand is that these dies have a relief outlet where excess lube escapes during sizing. Perhaps some rubbish is stuck in there?

Any clues on what i should be doing differently or how to fix the affected dies?

Thx Ross

Are you sizing the case just enough to chamber freely or winding the die down to touch the shell holder?
You maybe over sizing the case causing the neck to pucker and creating excessive headspace.

got a pic of the cases

Dents in neck or shoulder?

It’s almost always due to excessive lube


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Originally Posted by MSL

It’s almost always due to excessive lube


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Thats where i was heading too

Sorry, dent is in the shoulder.

Carpediem sent me a detailed reply of how to clean and polish the dies. He has had the same trouble with grit in Lee dies.

Vietnamcam, - i just follow the instructions about setting up the sizing die, -screw in to touch the shell holder and 1/4 turn more. How do you do it? I occasionally have trouble not sizing cases far enough and they wont chamber, which i fix by screwing the die in a little further. I have a pretty weak press which may not be helping.

Originally Posted by rossm-96

Sorry, dent is in the shoulder.

Carpediem sent me a detailed reply of how to clean and polish the dies. He has had the same trouble with grit in Lee dies.

Vietnamcam, - i just follow the instructions about setting up the sizing die, -screw in to touch the shell holder and 1/4 turn more. How do you do it? I occasionally have trouble not sizing cases far enough and they wont chamber, which i fix by screwing the die in a little further. I have a pretty weak press which may not be helping.

It is a annoyance of mine that most dies prescribe to set up the FL die as you have described.
The problem with those instructions is that they often cause an excessive headspace issue, they give those instructions to ensure that 95% of users ammo chambers but that means in some cases it is WAY oversized.

Over sized ammo will result in case web thinning and case head separation the consequences of which can range from a stuck part case in the chamber and the end of your shooting threw to serious injury and the END of your shooting.

The best way to set up FL size in my opinion is.
Remove the decapping rod/sizing button

You need at least a few cases that are tight to chamber.
Wind down to holder and up half a turn.

work with one case for a start.

There is a few things that happen as the die is adjusted down and how it happens and when is all dependent on your actual chamber dimensions vs your die dimensions.

With the die high it will neck size only, case should chamber as tightly as before sizing....adjust down 1/16th-1/8 turn.
As the die comes down it will start to size the walls of the case inward which will also push the shoulder forward as that brass has to go somewhere, case will be tighter to chamber or will not chamber....now you are actually sizing the brass but not yet the headspace dimension....wind down 1/16th turn.
Now you get to the nitty gritty winding the die down 1/16th turn at a time till it just chambers with little or no resistance this will be .001-.003" less than "Tight" to chamber.

Reinstall decapping rod and button and recheck, if it has now become tight to chamber you may need to revise your inside neck lubing as the button is pulling the shoulder forward.
For the life of your brass and the life of your eyes you dont want to be excessively FL sizing.

minimal measuring equipment is needed to reload like this.

For your peace of mind your comment about not chambering suggests you are not over sizing but you asked how I set up a die so there it is.

As above posts excess lube sounds like the culprit.

I like to screw it in bit by bit till the case just chambers nicely.


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How much lube are you using?

I've had the same problem when using 1 set of dies. These are the only ones I have that aren't vented and is a bit of a knack with the lube

had same issue backed die off 1/8 turn

It doesn't affect performance for hunting ammo. Just doesn't inspire confidence when loading for mates rifle

try cleaning the dies out again...meths on a cotton bud etc should shift anything in there....

Im guessing your using the LEE toothpaste lube???? if so chuck the shit away as far as you can NOW.......IF it hasnt cuased you grief yet it will soon.
dents in shoulder area are normally too much lube...I lube main sides of case with vasoline on my fingers,just a wee bit and twirl around...powdered graphite in lid of jar takes care of the necks inside n out. just dip case in,shake it gently off...I have some small steel shot in with the powder to help move it around.