Bullet/case run out Whats acceptable?

J

JRB

Guest
Just after some advise on reloading die procedure and expectation.
I have been doing an overhaul of my dies and reloading practices, to try to produce better, more accurate ammunition.
First up i have been 'caught out' producing loaded rounds with various defects, all of which i am fixing one by one.
The last one is case run out.

I am currently using a Redding bushing FL die, and Wilson seating die, so the only improvement, i thought, would be a custom die set. Now in time, i plan to get a new reamer and then custom dies to suit.
Now using a Rcbs case run out gauge, i can measure all my fired cases to less than .0005" runout.
Now using the FL die, the problems start. I have measured different bushings, steel and coated, for off center holes, tried them up and down! Yes when you turn them over you get a different resize amount. i tried Different case lubes and shell holders. I have tried necks both annealed and not.
I am getting from .001"-.003" thous, run out just from sizing the case. Now the bush is not fixed, but floats within the die body, so you can adjust the amount of case neck that gets resized. i tried shimming the bush perimeter with clear tape, and i can now reduce this to about .002" run out. This is a temporary solution at best, What is going on and is this to be expected?

Once I seat the projectile, about 50% are about .001" and the rest vary from .002" -.004" run out.
I trimmed and deburred, and deburred the deburr, to try to allow consistent seating.

All thought appreciated.
Jim
 
On the seater, try making a shim for your die base that is centered in it and which supports the case so that it very close to as far up in the die body as it will go, while the body of the die still rests on the base. This shim should be about case head sized, centered in the base. That should improve the fit of your sized cases in the die somewhat. Also, tell us what the runout is for a sized case with the correct amount of shoulder bump, with no bushing in the die. Another factor is how much the die is reducing the size of the fired case. The more it moves the brass from its fired condition, the more likely it is that runout will be introduced. What brand of brass are you working with? Are you turning necks? What caliber? Is this a match rifle or for field work?
 
Jim
If you told us what calibre you are reloading it might help. If you are talking something like a PPC or BR I would recommend you try a Harrels Die it is a relatively inexpensive solution to a multitude of case sizing issues. Not sure if they export though.
Dick
 
If you are measuring on the bullet just north of the case mouth the 0.0015 run out is acceptable on .308 through magnum cases.

In my personal experience a lot of run out is most likely the quality of brass. HOWEVER I get the best results neck sizing only with the Lee Collet Dies....................................................

I use bushing type dies only on turned necks on the BR size brass and insure they are set "squared to the press" correctly.

Lapua brass is you friend.

Best wishes
 
Thank you with some helpful suggestions,
it is a 6 Dasher with 270 neck on lapua brass, so just a cleanup, the shoulder is being pushed back just .0015" to close the bolt. i will try some with out the bushing and see.
Yes my seating die is very slightly deeper than my case, so i will get the base trued up.
I have been measuring the loaded round on the projectile, just back from were it would touch the lands.
I tried using the redding comp seater and it was less accurate than the wilson seater
I guess has anyone else experienced this?
what is acceptable run out for target work

is there a better way to lock down my FL die, could it be an issue?

Jim
 
I've found that Lee lock rings with the rubber O rings do a superior alignment job, but they don't hold their setting. You need to redo that each time you fit them.
 
JRB,

1. leave your sizing die lock ring loose and size a piece....what is the runout?

2. what is the runout sizing without the bushing?


If the sizing die is the problem, here is the potential problems:

1. Shellholder, however, you said you checke this.
2. Press is not in alignment.
3. threads of die are not perpendicular to cavity.
4. the bottom of the threaded insert that holds the bushing in is not perpendicular to cavity.
5. Bushing, however, you said you checked this.


Here is the order I would check:

0. Remove bushing and size
1. Change shellholder
2. Change bushing
3. Leave die loose or put oring under lock ring.
4. Change presses (use same shellholder).
5. Borrow a friends die that produces straight cases, check it in your press.

When you stated that you got better runout when you tightened the diameter clearance of the bushing to the die, leads me to believe that either the bushing or the insert holding bushing in is the problem.

Once you get the sizing issues worked out, the wilson seater is another animal. Most of my problems with them has been with the cap and stem.

Hovis
 
Thank you for all your suggestions,
looks like i have a busy week end coming up!
regards
Jim
 
HovisKM said:
JRB,

1. leave your sizing die lock ring loose and size a piece....what is the runout?

2. what is the runout sizing without the bushing?


If the sizing die is the problem, here is the potential problems:

1. Shellholder, however, you said you checke this.
2. Press is not in alignment.
3. threads of die are not perpendicular to cavity.
4. the bottom of the threaded insert that holds the bushing in is not perpendicular to cavity.
5. Bushing, however, you said you checked this.


Here is the order I would check:

0. Remove bushing and size
1. Change shellholder
2. Change bushing
3. Leave die loose or put oring under lock ring.
4. Change presses (use same shellholder).
5. Borrow a friends die that produces straight cases, check it in your press.

When you stated that you got better runout when you tightened the diameter clearance of the bushing to the die, leads me to believe that either the bushing or the insert holding bushing in is the problem.

Once you get the sizing issues worked out, the wilson seater is another animal. Most of my problems with them has been with the cap and stem.

Hovis
Click to expand...

I had some time last night, so I tried most of the suggestions, things are improving but not consistent, or the error is not consistent. I have not attempted seating any projectiles, just the re size. Once i get this sorted i can go to the seater.
I have tried, other bushings, with out bushings, shimming the bush, and not, measuring the bush, turning it over.
Now i measured a few bushings with my micrometer and found varying differences, but since they have about .006" clearance in the die body i could not see any advantage in chasing a thou or two in the bush. also i was only measuring from the inner to the outer, not the inner circle or diameter. One thing that did cross my mind was if the coated bushes are true after the coating has been applied? could they be oval?
Are the Wilson bushes finish ground, not drilled, as they seemed more consistent with my simple measurement.

Leaving the lock ring loose and the die loose, but i cannot repeat results over, so it is hard to know if they are real results, or just case by case reactions.
Now after all this, i can get results from .0005"-.002", which is a huge improvement from the start. Mostly they are .001", a few less, and very few more. So is this the best i can achieve, for now.

I measured all my cases before i started, and they were 50% from 0-.001", now i can only attribute this to them being annealed, possibly poorly at that, by eye and not machine, which may have caused the variation, spring back etc.

Now i did as much as i could with the bushing, and were it sits in the die body, as there is about .005" or more clearance around the bush, but any attempt to get consistent results, shimmed or not failed.
I guess unless the bush is solid, it can not change the neck run out or modify it, after it is set?
Another thing i found was that having half the cases at 0 and half at about .001" was that when they are at .001" you can not really get them back to 0! when they are at 0 you can get either a 0 or .001" result after re sizing.

Now the other problem i have is the 6 BR cases have been worked hard for 18-19 firings,
Can this cause a variation in neck wall thickness, as i am seeing more variation than before?
When do cases just need to be replaced?

I will try changing presses tomorrow and see what happens,
I need some more ideas, or correction!
Jim
 
Last edited by a moderator:
18-19 firings? Try this experiment after 1 firing or 2. That brass flows all over the place in 19 firings and is hard as a pet rock
 
JRB,

I think you are getting tunnel focused on the bushing clearance. Horizontal and Vertical cleanance of the bushin is a non-issue, forget about it. The bushing could be a problem but not the clearance. If you have tried several bushings, then bushings are not the issue either.

1. Different Press
2. Different Shellholders

If things persist after checking these, get a different die, something with the die is not in proper squareness or alignment.

Hovis
 
Dusty Stevens said:
18-19 firings? Try this experiment after 1 firing or 2. That brass flows all over the place in 19 firings and is hard as a pet rock
Click to expand...

Are you suggesting that neck thickness can vary after many firings? from brass flow?
Is it from FLS? or firing?
often the case necks are not square after a few firings, before being trimmed. if this is from the FLS action pushing the brass up, than i guess it passes through the neck, so could effect the thickness?
Jim
 
Dusty Stevens said:
Brass flows from firing and sizing. 20 firings and my brass isnt worth measuring
Click to expand...





I'm glad you told me that…… I set 4 agg. records with a Dasher at 1000 yds. with brass that was fired a 100 times. it only needs trimmed about twice a year so it sure doesn't flow much. It does get annealed every time……. jim
 
HovisKM said:
JRB,

I think you are getting tunnel focused on the bushing clearance. Horizontal and Vertical cleanance of the bushin is a non-issue, forget about it. The bushing could be a problem but not the clearance. If you have tried several bushings, then bushings are not the issue either.

1. Different Press
2. Different Shellholders

If things persist after checking these, get a different die, something with the die is not in proper squareness or alignment.

Hovis
Click to expand...

Hovis,
i am getting to the bottom of this, and i tried another 10 fired shells, marked each one, and measured run out at every step, including annealing and trimming, to loading the case.
now first up, i had zero run out up to FLSing. To FLS i tryed 6 cases with varying amounts of lube and shellholder positions, and i still got a 50-50 split from 0-.001" run out.
now i than changed to another Redding comp shell holder and sized another 4 and they all sized with zero run out! I will size another 10 tomorrow, just to be sure.
I continued the process with trimming etc right through to seating the bullet, i was surprised that when seating i had two more true necks gain run out and one bad neck return to zero run out.
After loading all 10 i had 6 with zero, 3 with .001" and one with nearly .002" run out.
now after trimming i chamfered the neck and ran the nylon brush in and out about 3 times to clean any burr.

Now i know my Wilson seater is a bit oversize for my case, as it was not cut with my reamer, but do you have any suggestions? i did give it a good clean and it is a newish die.
My seating process did not show good results, and also i am getting varying neck tension when seating.
Can anything be done to correct this, these are br cases with 19 firings, i also have some 223's with the same number of firings, and they are very consistent in seating pressure.
Jim
 
Is your measurement of run out the total run out ? I use Harrell's dies and one Redding all FL. bushing dies, and these have less than a .001 total run out, but i'm sizing on a coax press. My seaters are made from my reamer…….. jim
 
JRB said:
Now i know my Wilson seater is a bit oversize for my case, as it was not cut with my reamer, but do you have any suggestions? i did give it a good clean and it is a newish die.
My seating process did not show good results, and also i am getting varying neck tension when seating.
Can anything be done to correct this, these are br cases with 19 firings, i also have some 223's with the same number of firings, and they are very consistent in seating pressure.
Jim
Click to expand...

Make a variable seater base that will push the case further up into the tapered Wilson seater die and therefore remove the die to case slop, or remove some material from the Wilson seater bottom, if you have a lathe, and this will accomplish the same thing.
 
Waaay back in the black and white days of Precision Shooting, I read an article that reported the results of two modifications of Wilson seater dies. One was shortening the die to improve the fit. As has been mentioned, the same thing can be done with a special base, that raises the case in the die. The other mod. was to carefully set up the seater stem in an accurate lathe, and recut the cavity so that it was better centered.

In the short range game, with thin necks, and FB bullets that have a pressure ring, with the bullets a little over an eighth of an inch in necks, if the cases are straight, and the seater does a poor job of keeping bullets aligned with them, I have pretty much proven, on paper, that as long as the seating is into the lands, that runout on the bullet does not matter at all. This contradicts my previous, long held position, but the test was conclusive. The groups were as small as any that I have shot, with straight ammo. One time, I was stuck using a seater that I know produces very inconsistent results, because of a non standard chamber that would not allow my cases to fully enter my Wilson die. The barrel was a good one, and it shot outstanding groups. Previously I had measured runout on bullets seated with that die, and it was all over the place, up to some large numbers.
 
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