Bushing drag on neck with FL sizing die

[BCoates]

I'm using a Whidden FL bushing die without the expander to size my .308 Lapua cases. I'm using Redding TiN coated bushings and have set the die up so that the bushing floats slightly. I'm using imperial wax to lube the case bodies and necks. My problem when raising the press handle after sizing a case, I can feel the bushing dragging on the neck of the case. I know it is the neck that is dragging because cases are coming out of the die with longer shoulders than when they went in (headspace is getting larger). How do I remedy this? I'm only sizing the neck down 4-5 thousands from the fired diameter.

 

[jlow]

If they are dragging, two things may help. One is to anneal your necks so that they have less spring back which is what is resisting the sizing and allowing the neck to hold on to the bushing. The other is to size in more than one step – that should also decrease spring back.

 

[243winxb]

What happens without a bushing? If like a Redding, the die without a bushing may still size the neck, depends on fired neck diameters. My guess is you need the die polished. Not a bushing problem?? My 243win die, without bushing, sizes the neck to .278" OD when i run a 308 fired brass into it.

 

[pacificman]

I think there needs to be a bit more info to solve your problem as it sounds like your bushing is too small. Need to know what your rifle chamber neck diameter is and as you probably already know you will need at least a couple thousands neck clearance in your chamber. At least that is what it sounds like to me.

 

[jlow]

He is seizing down 4-5 thousands which is quite a bit...

 

[ridgeway]

Take the bushing out and see if there is any contact with the case and the hole going through the top of the die.

 

[BCoates]

I have sized cases without the bushing and don't get drag on the neck. I'm sizing down in two steps, and I'm on the first sizing step now. My chamber is .3435", so my first sizing is with a .339 bushing. Then I will size again with a .336 bushing. My loaded round diameter is .3375-.338" using unturned Lapua. The brass has only been fired 2 times and have not been annealed.

 

[243winxb]

because cases are coming out of the die with longer shoulders than when they went in

Can be normal for a FL sizing die. The TiN coated bushing needs very little lube, if any at all. Try without wax after cleaning bushing. Do lube the case body, none on shoulder. I size down .008" in 1 step, not a problem for me. Interesting problem??

 

[jlow]

I check my own 308 brass before and after and those numbers are not unreasonable. I am a bit amazed that you can actually pull on the neck hard enough to change headspace… How much longer do they get?

 

[BCoates]

The headspace is growing anywhere from 0.0005" to 0.0015".

 

[jlow]

That is really strange, do you know if it is growing with which bushing or is it both?

 

[Patch700]

Are you positive that it's not partially sizing at the datum line, yet not quite bumping the shoulder yet?
Have you tried taking a measurement of your brass diameter at the datum line on a piece of brass that is not yet sized and then compare it with one that has been sized ....
Theoretically you shouldn't be getting stretch from a tight bushing when used without an expander , but rather some slight crush one would think.

 

[Tzed250]

From what I have gathered from the knowledge on this site is that if you run a case into a FL die without it going all the way the case will lengthen before reaching the point where the shoulder is set or set back.

 

[ridgeway]

The headspace is growing anywhere from 0.0005" to 0.0015".

This is not from a case dragging, you aren't touching the shoulder yet. Lower your sizer and keep trying until it you are moving the shoulder.

 

[jlow]

Good point. I was only thinking relative to me Redding Type S bushing neck sizer die which does not size the case. If your die is sizing the case (and it looks like it will), it will in fact reduce the diameter of your case and that extra material will give you extra headspace. Normally with something like a Redding Type S bushing full length sizer die that is adjusted properly, the case will lengthen as you start sizing but the die will bump the shoulders down when it meets the shell holder if it is adjusted properly.

If your Whidden FL bushing die is not properly adjusted to give you a proper shoulder bump, your headspace will increase.

 

[Patch700]

The headspace is growing anywhere from 0.0005" to 0.0015".

This is not from a case dragging, you aren't touching the shoulder yet. Lower your sizer and keep trying until it you are moving the shoulder.

And herein lies a possible problem.... If he is using a Widden die then rite off the bat you know that it was cut with kiff's reamer , that being said he may have a slightly oversized chamber as compared to the dimensions of the die..
By simply running the die further down so it indeed makes contact with the shoulder he may also be over sizing the brass at both the datum line and at the base. So essentially he may be relegated to over work his brass in the name of achieving uniform shoulder bump. Me personally I haven't had case stretch from using a tight bushing when not dragging the neck across an expander ....

 

[243winxb]

Re: Bushing drag - a wild guess

Bushing - The bushing stop must be square to the die body. If its not, the neck will be sized crooked by a few degrees. After sizing, the case is withdrawn and the bushing comes in contact with the bottom stop. This is where the resistance would be felt as the neck is extracted from the bushing on a different angle. The bushing size marking should be facing the case mouth also. Or in other words, the neck is pushed to one side going up. The neck is being bent back when going down. Yes, a wild guess. The Redding die has the bushing sitting in a cylinder with only .010" clearance or .005" on each side maximum. Not much room for a crooked bushing?? But the die is NOT Redding. http://www.google.com/patents/US5649465 :-\ ;D

 

[BCoates]

That is really strange, do you know if it is growing with which bushing or is it both?

I sized everything with the .339 bushing and the shoulder was getting longer. I just finished sizing again with a .336 bushing and had some of the same issues. This time I was trying to push the shoulder back, but I could still feel drag on the neck. My headspace measurements varied by about 0.002" (from 0 bump to 0.002" bump). Some cases I had to size twice because the headspace measurement was too long. I'm having the same issue with both bushing, so I think that my brass is getting to work hardened and needs annealing.

 

[BCoates]

Are you positive that it's not partially sizing at the datum line, yet not quite bumping the shoulder yet?
Have you tried taking a measurement of your brass diameter at the datum line on a piece of brass that is not yet sized and then compare it with one that has been sized ....
Theoretically you shouldn't be getting stretch from a tight bushing when used without an expander , but rather some slight crush one would think.

I did take some diameter measurements at the shoulder and it is sizing down about 0.002".

 

[ridgeway]

How fast are you running those cases in and out of the die? Since you mentioned you had to size a case a second time to bump the shoulder leads me to believe you are running the case too fast in and out of the die. If you are whizzing them in and out, slow down and let the ram can over and lock for like 5 seconds. This allows the brass respond for consistent shoulder bump.

What type of lube are you using? Lubing the necks? If you aren't using Imperial, get some and try it. There will be resistance going in and out of the die, but not enough to skew any sizing dimensions. Any part on the brass coming out really shiny?

Annealing definitely helps consistency. Do it every firing or every other.