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Perplexing Sizing Issue

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03 May 2004, 02:30
BECoole
Perplexing Sizing Issue
A friend gave me a bunch of 2x fired LC .223 brass that he had bought from one of the major suppliers and shot through his guns. I Full-Length resized them using Imperial and trimmed and polished them. I threw out any cases that did not resize with normal effort. In this batch, there was about 1 or 2% that flat out wouldn't go into the resizer.



After coming out of that sizing operation the length of those sized cases is 62 and longer (disregarding the fist 2 digits, like 3.462", because I'm using a Stoney Point Case gauge).



After they come out of my gun (firing 3), they are 59.



When I full-length size those 3x fired cases in the same sizing dies as before, they come out 56!



Now, I wouldn't have given this a thought except that when I tried to eject an unfired round, I had to pound the gun on the ground with my hand on the charging handle and I had one that would not easily chamber.



My die is screwed down to a crush fit on the shellholder every time I size. I even experimented with the decapping rod removed. Same results.



Even if I run a case through 3 times, it still doesn't set the shoulder back. Only after being fired through my rifle does it size correctly.

Why isn't the die fully setting back the shoulder on the first sizing?
03 May 2004, 02:53
Hot Core
Quote:

... Why isn't the die fully setting back the shoulder on the first sizing?





Hey BECoole, I'd suspect it is something as simple as "Spring Back". When I Form 350RemMag cases from other Belted cases, I get it too.



There are a couple of ways to defeat it:



1. File the top of the Shellholder down just until a squashed case will go in easily. THis requires re-adjusting the FL Die for the initial Forming and then re-set it for proper Sizing.



If you go this route, you might want to save and mark the Shellholder just for this operation and use another one for your regular FL Sizing.



2. Reduce the width on a 0.002"-0.004" Feeler Gauge and slide it "under" the case when it is in the Shellholder. This will hold the case up enough to allow the FL Die to do just enough more Sizing to correct your problem.



NOTE: Remove the Expander from the FL Die so as not to "Hole Punch" the Feeler Gauge. No comment on "why" I know this.
03 May 2004, 02:57
Savage99
The headspace dimension created by a FL die and shell holder combination is not some exact number. Neither is your chamber.

If you have another shell holder try that and see if it pushes the case in more. If not you can sand your shell holder or die down to get the cases to fit or send the die and cases to an RCBS and if they made the die they will make it work.

Also Redding sells shell holders of different heights. It's a lot easier to buy a Lee shell holder and sand it down however.
03 May 2004, 03:15
beemanbeme
Am I confused?? As I read the post, the rounds are chambering but his problem is in extraction. That being the case, nothing you do to the the die nor shell holder is gonna change that.
What sort of load are you shooting? What rifle?
03 May 2004, 05:47
BECoole
Quote:

Am I confused?? As I read the post, the rounds are chambering but his problem is in extraction. That being the case, nothing you do to the the die nor shell holder is gonna change that.
What sort of load are you shooting? What rifle?



Well, some of them weren't chambering too easily. That's why I was extracting some of them. So neither the chambering or extraction was proper. I tried the forward assist on some of them, and one was so bad that it wouldn't even dimple the primer until I let the bolt fly on it a couple times. (I'm a Persistent bugger, no?)
I'm shooting an AR15.
03 May 2004, 05:54
BECoole
Quote:

I'd suspect it is something as simple as "Spring Back". When I Form 350RemMag cases from other Belted cases, I get it too.




OK. I can see that, but I still find it perplexing that if I take the same case and run it through the sizer twice in a row, it comes out the same too-long length. I'd think the first try would size it some, then the 2nd or 3rd pass would size it down the rest of the way. Man, this is worse than calculus!

Quote:


2. Reduce the width on a 0.002"-0.004" Feeler Gauge and slide it "under" the case when it is in the Shellholder. This will hold the case up enough to allow the FL Die to do just enough more Sizing to correct your problem.

NOTE: Remove the Expander from the FL Die so as not to "Hole Punch" the Feeler Gauge.



That's an interesting suggestion. I will try that before I go hacking on my dies or shellholders.

Thanks!
03 May 2004, 08:06
243winxb
Your load may be to light to fully expand the brass on firing. The case gets fatter and shorter on firing. As for sticking in the chamber (unfired), this is common with brass fired in other guns with hot loads. There is a part of the brass near the head that the die can not size. This is where it gets stuck.
03 May 2004, 08:23
243winxb
if you start with 62 then fire the ammo in your gun, then full length resize they come out of die at 56 Is that not .006" shorter?? Less headspace?? dont use a stoney point gauge.
03 May 2004, 09:07
Burke
Would a small base body die help any at this point?
03 May 2004, 09:21
BECoole
Quote:

if you start with 62 then fire the ammo in your gun, then full length resize they come out of die at 56 Is that not .006" shorter?? Less headspace??




Exactly! And they even come out of my rifle with .003" less headspace.

Quote:


dont use a stoney point gauge.



Why not? It's just a fitting for dial calipers that gives a consistent point of reference off the case shoulder.
03 May 2004, 10:19
TBF
I am just trying to understand, so like bear with me...

Your chamber is " sizing " the brass smaller than the die ?
And you are measuring this with a Stoney point, with the correct insert ?

How does other brass size with the same die ?
As in known good brass.

Travis F.
03 May 2004, 10:39
Ol` Joe
Are you lubeing your case mouths?

I suspect your expander ball is dragging on the case pulling the shoulder out a couple thou`. This is why you find the cases are over spec straight from the die. When you chamber the round the shoulder is pushed back a hair by the bolt slamming home (turn bolts do it easy also because of the camming action when closeing) and fire forms to the chambers diamention.

Try removeing the expander and see if the shoulder still changes headspace.

Just a thought............
03 May 2004, 15:26
BECoole
Quote:

I am just trying to understand, so like bear with me...

Your chamber is " sizing " the brass smaller than the die ?




Yes.
Quote:


And you are measuring this with a Stoney point, with the correct insert ?

How does other brass size with the same die ?
As in known good brass.

Travis F.



Yes.
Seems OK, I haven't tried any other brass yet with this barrel. I never had issues with the last barrel, a factory match barrel. It's a brand new match barrel and I only encountered this problem while I was breaking it in.
03 May 2004, 15:28
BECoole
Quote:


Try removeing the expander and see if the shoulder still changes headspace.




I tried that and it made no difference.

I think I need to shoot this brass/barrel combo a little more.. this just ain't right.