FL sizing issues...Fixed!

[Joe C]

Greetings.

I need some assistance. Previously I have only been neck sizing my brass for my .260AI. That has worked well but as time goes on I foresee the need to bump the shoulder back. Problem is, I've tried to do just that with two different sets of Redding dies and while it sizes it down the case becomes very tight when trying to close the bolt.

I have done comparison measurements with a fired case and sized case to prove to myself that it is indeed sizing down the case. Any help would be appreciated.

 

[Erik Cortina]

Re: FL sizing issues...

Joe, you need to screw the die down more. What is happening is that as the sides of the case are squeezed down, the case shoulder moves forward making case really hard to chamber. Keep turning die down (small increments) until shoulder is pushed back just enough so that the bolt closes on a resized case.

 

[fguffey]

Re: FL sizing issues...

I need some assistance. Previously I have only been neck sizing my brass for my .260AI. That has worked well but as time goes on I foresee the need to bump the shoulder back.

Joe, you need to screw the die down more. What is happening is that as the sides of the case are squeezed down, the case shoulder moves forward making case really hard to chamber. Keep turning die down (small increments) until shoulder is pushed back just enough so that the bolt closes on a resized case.

Joe C., If the Redding full length sizing die not return the case back to minimum length/full length size the case the die did not make it to the shell holder. When the die does not make it to the shell holder the case does not get sized. Next time determine the gap between the die and shell holder to determine if the case was sized, anything keeping the die off the shell did not get sized.

Then there is that part about the bolt not closing, it is possible to determine the difference in length between the chamber from the shoulder to the bolt face and the length of the case from the shoulder to the case head, to close the bolt the case length must be shorter than the chamber length.

Neck sizing, reloaders perpetuate a myth. most believe it is possible to fire to form a case and neck size it 5 times then start over by full length sizing. The case has been fired 6 times, the case work hardens, when the case is work hardened the case increases its ability to resist sizing. I suggest when you assume the case is being sized check the gap between the bottom of the die and top of the shell holder. As has been mentioned, to increase the presses' ability to overcome the cases' ability to resist sizing screw the die down.

F. Guffey

 

[SmokinJoe]

Re: FL sizing issues...

What Erik said is true, and that phenomena is very misleading to many when they first try to bump shoulders. I would strongly recommend that you get some measuring equipment (I use Stoney Point/Hornady) and some Skip's die shims. It also helps with consistency to re-anneal the brass before you get into shoulder bumping, and work on consistent case lubrication methods, too. You can easily master all these things, just work at it and measure, measure, measure at first. Read all you can find about the subject (do a search ). Good luck with it, and welcome to the shoulder bumping club; I think you will like the results once you get it down. I have used only two dies for my reloading for quite awhile now - a bushing type FL sizer with die shims for precise adjustment, and a Wilson in-line seater with arbor press.

 

[mikecr]

Re: FL sizing issues...

There is a recent thread around here about bump dies, you might search.
What you're seeing shows that a FL die is not a bump die. It's more like a re-forming die.

By the time you jam & squish the entire body in/down just to get your shoulder bumps, your cases will no longer be the fireformed cases they are now. And with all that added springback going on, you're likely to measure headspacing as inconsistent(compared to simply bumping).
So just keep in mind, FL sizing and bumping are different. You're seeing this.

 

[fguffey]

Re: FL sizing issues...

And with all that added spring back going on, you're likely to measure head spacing as inconsistent(compared to simply bumping).
So just keep in mind, FL sizing and bumping are different. You're seeing this.

There is no such think as shoulder bumping, the shoulder can not be bumped without case body support. That leaves sizing the case from the shoulder to the case head. That leaves full length sizing and nothing. Then there are threads on the die and press, threads make the die adjustable to the shell holder.

Options: There are Skip's shims, remove the die, add a shim replace the die, back to the threads on the die and in the press, how does a reloader verify the shim added reduced the die's ability to size a case?

There are shell holders from Redding, the Redding competition shell holder increases the deck height of the shell holder from .002" to .010" in increments of .002" meaning the Redding competition shell holders comes in a box of 5 for $40.00. Problem, the OP does not have a problem with increasing the length of the case from the shoulder to the head of the case, he has a problem with the case being too long, meaning he has to figure a way to increase the press, die and shell holder's ability to shorten the case.

Unless: Someone has invented a minus shim, I have been doing that for years, I add shims between the deck of the shell holder and head of the case. Adding a shim between the deck of the shell holder and case head increases the press, die and shell holder's ability to reduce the length of the case.

It is not necessary for a reloader to spend the rest of their life addicted to the use of shims, shims can be used to solve a problem, after it is determined the case is whipping the press because it does not have the ability to overcome the cases ability to resist sizing, the reloader can move on to solving the problem. Sometimes that means adjusting the die down an additional 1/4 turn etc..

I form cases for short chambers, I shim the case off the deck of the shell holder, in the old days it was common practice to grind the bottom of the die and or top of the shell holder. The deck height of the shell holder should be .125".

F. Guffey

 

[Joe C]

Re: FL sizing issues...

I appreciate all the advice. What seems to be getting missed here, perhaps by me, is that I am able to completely resize the cases...I can make them WAY shorter and the O.D. goes down as well. But even when I do that they will not go in the gun properly. Bumping the shoulder back isn't really the problem, it is getting bumped back. Originally I thought perhaps there was something wrong with my dies, but after trying it on two sets, nah...

So keep the thoughts coming as I have to get this figured out or it is going to drive me bonkers...and it's a short drive fellas...

 

[BoydAllen]

Re: FL sizing issues...

Use a marker to color the whole exterior of one of your sized cases that is tight, chamber it, and short cycle the bolt a number of times, then examine the case to see where the color has been scrubbed off. How do fired cases chamber?

 

[Erik Cortina]

Re: FL sizing issues...

Joe C, how are you measuring shoulder bump?
Make sure brass OAL length is below max as well.

 

[artbosco]

Re: FL sizing issues...

Perform no half measures like neck sizing, followed by the occasional body sizing. Brass dimensions and hardness get totally out of syn when such extremes are applied. [That's akin to jumping in a shower and washing from the neck up everyday then washing from the neck down once every two weeks. Yuck!]

Throw the old brass away. Start over. Religiously F/L size from now on. You'll only need two dies, a F/L die [preferably a F/L Bushing die] properly adjusted, then readjusted when needed, and a Seater.

 

[fguffey]

Re: FL sizing issues...

I can make them WAY shorter and the O.D

What seems to be getting missed here, perhaps by me,

Or me, we are taking about the length of the case from the shoulder to the head of the case, the O.D. refers to the diameter of the case.

I use standards and transfers. I use a standard to check the accuracy of the die/shell holder combination. If the case will not allow the bolt to close a reloader should be able to determine by 'how much'. If the case is not sized the reloader should be able to determine 'by how much' before lowering the ram in thousandths.

F. Guffey

 

[Joe C]

Re: FL sizing issues...

SCHAZAM! Got it fixed thanks to all of your great comments. As it turns out, while various shell holders may measure different thicknesses, that does not mean they are different from the inside to the top where the die lands...and this is something I should have remembered to check.

Using Boyd's advice of marking the case and thinking through some of the comments from guys like Guffey I started looking more closely knowing I'd seen this before but not remembering where...

Then I started measuring the inside depth of shell holders. Long story short, 5 shell holders, only .004" difference between them on the inside but as much as .020" on the outside (not counting the stem of course). So I took one out to the shop, put it on the lathe and started cutting the top of it until I got the sizing desired. Easy fix...but sometimes the easiest things drive you the nuttiest! LOL! And now I remember where this problem occurred previously, with my .240nmc, which would explain why I stamped that caliber into a specific shell holder because it was turned down as well.

So! Thank you all for your gracious and generous help. Keep Calm and Shoot On!

 

[fguffey]

Then I started measuring the inside depth of shell holders. Long story short, 5 shell holders, only .004" difference between them on the inside but as much as .020" on the outside (not counting the stem of course). So I took one out to the shop, put it on the lathe and started cutting the top of it until I got the sizing desired.

"started cutting the top off until I got the sizing desired" Difference between shell holders as much as .004", had you measured the deck height you would know how much metal was removed. I do not grind the top of the shell holder or bottom of the die to lower the deck height, but JIC* I did I would want to know the 'desired height'.

* Just in case

F. Guffey

 

[BoydAllen]

One more thing...You had stated that you were definitely bumping your shoulders, when it turns out that you had not been. Do you have a tool to measure shoulder bump, and did you use it on the cases that were tight, comparing them with fired cases? It seems to me that you may have been assuming what was taking place without measuring it. I measure shoulder bump every time I put a FL die in a press, or change lots of brass. This is because cases work harden as they are repeatedly fired and sized, and a die set for a hard case, will bump a new one too much, and a die set for a new case will not bump a work hardened one at all.

 

[Joe C]

One more thing...You had stated that you were definitely bumping your shoulders, when it turns out that you had not been. Do you have a tool to measure shoulder bump, and did you use it on the cases that were tight, comparing them with fired cases? It seems to me that you may have been assuming what was taking place without measuring it. I measure shoulder bump every time I put a FL die in a press, or change lots of brass. This is because cases work harden as they are repeatedly fired and sized, and a die set for a hard case, will bump a new one too much, and a die set for a new case will not bump a work hardened one at all.

I do have a way to measure. Not sure if it is right but I have a set of rings for different calibers that I can use with my surface plate and dial mic...but I would be curious to know what the rest of you use as I'm always wanting to get better!

 

[BoydAllen]

I like the Hornady tool (caliper attachment) that they have mistakenly labeled a headspace gauge. It is really a comparator. One thing that I think is important, no matter what tool or setup that you use is to reseat the fired primer well below flush (or remove it) before measuring a fired case.

 

[gotcha]

Joe C, Thanks for your response .......... So many people here post questions then don't have the common courtesy to even give a simple thank you or post their follow up results......... Your response enabled others to learn from your experience. That's what the forum SHOULD be all about !!!! JMHO Dale

 

[bigedp51]

Greetings.

I need some assistance. Previously I have only been neck sizing my brass for my .260AI. That has worked well but as time goes on I foresee the need to bump the shoulder back. Problem is, I've tried to do just that with two different sets of Redding dies and while it sizes it down the case becomes very tight when trying to close the bolt.

I have done comparison measurements with a fired case and sized case to prove to myself that it is indeed sizing down the case. Any help would be appreciated.

We live in a plus and minus manufacturing world and semantics didn't bump, push or force the shoulder back..........mechanical force did.

The mechanical force is controlled by the person pulling the handle of the press.

The person pulling the press handle needs to know what happens when he pulls the handle and have a way to measure the location of the blue, red and green dotted lines.

And as Boyd Allen stated having a way to accurately measure it.

I prefer the word bump because if I'm hammering nails and hit my thumb it hurts less if I say I "bump" it instead of saying I smashed the crap out of it.

And Forster doesn't seem to have a problem with semantics.

The Hornady case gauge below and digital vernier calipers with big numbers is the greatest thing ever invented for people with chronologically gifted eyesight that can't afford a braille gauge.

 

[bigedp51]

I like the Hornady tool (caliper attachment) that they have mistakenly labeled a headspace gauge. It is really a comparator. One thing that I think is important, no matter what tool or setup that you use is to reseat the fired primer well below flush (or remove it) before measuring a fired case.

Semantics...........can be a slippery slope.

How close do you have to be before you are no longer comparing.

And a protruding primer tells its own story.

 

[Joe C]

After further great comments I spent about 10 minutes on the lathe again and made a gauge similar to the Hornady one only with a 40° shoulder angle for my Ackley cases. Thank you again everyone for helping me and inspiring me to get even better. As it turns out, I am now setting the shoulder back .001" with the dies and the newly turned shell plate. The bolt now closes properly on the round. Again, much thanks!