Shortening dies?

Nov 24, 2013
991
90
28
Dallas
#1
No, this doesn't have anything to do with Crisco (shortening... get it??).

I have found myself in a position of having to shorten a couple of dies lately, and I'm having problems diagnosing what's behind that. Let me explain. I have found that in order to get the dies (two FL resizing dies and a factory crimp die) set the way I want them, I've needed to grind the bottom of the dies in order to get the cases far enough up in the dies to do what needs to be done. In other words, the dies as delivered have been bottoming out on my press before I get the shoulder bump/crimp that I want.

I am running the following hardware:
  • Forster Co-Ax press
  • Forster .223 Rem FL sizing die (new)
  • Forster .204 Ruger FL sizing die (new)
  • Lee .204 Ruger factory crimp die (new)
My first thought was that I had somehow bent/tweaked something with my press that was causing this issue, but the press shows no obvious signs of it, and beyond that, looking at the design of the press, the only thing I can think of that would cause something like this would be if the side links (that connect the handle to the ram) were to somehow get magically tweaked. Regarding the die adjustment, I am aiming for the typical .001-.002" shoulder bump (based off of cases fired in my rifles), so I'm disinclined to believe that this is the issue; one thing I will say is that both the .204 Ruger and the .223 Rem rifles in question are running custom/gunsmithed barrels, so it's likely that the headspace on them is pretty close to the "GO" measurement... so I s'pose that it's possible that the dies were built to bump the shoulder on a longer (than minimum) fireformed case, but I dunno.

One other thing I should note is that this is the first time I am using these dies, so it's not like they worked once upon a time and now they don't... but I just get the feeling that I'm overlooking something...
 

KZP

For Sale Access
Mar 11, 2017
101
28
28
Raleigh, NC
#2
I talked to another guy at the range once and he mentioned a similar issue. His solution was to grind off a little material from the top of his shell holder using a flat sharpening stone. This gave him more depth into the die.

I've also read that Redding dies are more aggressive on the bump, so you can back them out slightly to get the correct value. I have Redding 308 dies and found it took a little backing off to get the bump I wanted.
 

spife7980

Full Member
Feb 10, 2017
3,369
458
83
TX
#3
I was just about to bring up the shell holder too but its a coax so nvm. Are you screwing them down with the press all the way up? Could you try to screw them down a bit lower than they go at full stroke and see if that will give you a bit of cam over? I know, it shouldnt but its an easy thing to test. Oh, you have switched the jaws to the small sides right?
 
Nov 24, 2013
991
90
28
Dallas
#4
I was just about to bring up the shell holder too but its a coax so nvm. Are you screwing them down with the press all the way up? Could you try to screw them down a bit lower than they go at full stroke and see if that will give you a bit of cam over? I know, it shouldnt but its an easy thing to test. Oh, you have switched the jaws to the small sides right?
The way I'm installing the dies is to remove the decapping pin/case mouth expander, run the ram all the way up, screw the die down until it touches the shell plates (which have been switched to the small side), then backing it off about 1.5-2 turns.

Lower the ram, insert a greased-up case, and raise the ram. Lower the ram, check the case to see how far it made it up into the die... the case mouth is where it's easiest to check. Usually, it's pretty easy to see how far along it's length the case mouth has been sized down. In any event, another light coat of case lube, turn the die down about half a turn, and basically sneak up on the shoulder bump that I'm after. What I've been seeing is that as the case mouth gets sized down, the shoulder tends to move forward, right? The brass that's being squished out of the case mouth has to go somewhere... Anyhow, right as I get to the point of having the neck fully sized down (but not re-expanded, because I removed the decapping pin/expander ball) and the shoulder pushed back to nearly my initial shoulder measurement (on the fired case; maybe initial measurement +.002" or so), I start getting slight cam-over on the press. I double check it by cycling the ram without a case in the jaws, and if I still feel it, I conclude that I've bottomed out the die.

At that point, I re-check everything to make sure that I haven't gotten a case of the stupids (which has sadly been known to happen), re-zero my caliper (I'm using Mitutoyo digitals and the Hornady head space comparator bushings), re-measure the case that I've been using to set the die, and once again conclude, yep, the die is too long. Out to the bench grinder, sparkin' and spitzin', clean off/out the die with whatever's handy (usually WD40 or similar), run a patch through the die a couple times to make sure that the metal dust has been removed, and back in the press to try again. Once I get it dialed in, I do a little clean up to my hack job on the bottom of the die... bevel the edges with jeweler's files and run the bottom face of it over a diamond stone for a few minutes to get the bulk of the grinding marks off. I have no illusions that the bottom face is square to the bore of the die, but unless it's WAY off, I don't see how that could be a problem.
 

spife7980

Full Member
Feb 10, 2017
3,369
458
83
TX
#5
That is strange, not sure what else to do then. I have a coax but the only forster Ive used is for a 6xc and I still have enough adjustment left over to buckle the case probably. My redding 223s work just fine with the same amount of adequate adjustment. No 204 or crimp dies to test on mine.

Just as a point of curiosity, what is your measurement to the shoulders on your fired? I know it wont be exact but it should be in the same ball park. My 223 is right around 1.560 with the hornady comparator if I remember correctly and I size back top 1.557.
 
Nov 24, 2013
991
90
28
Dallas
#7
That is strange, not sure what else to do then. I have a coax but the only forster Ive used is for a 6xc and I still have enough adjustment left over to buckle the case probably. My redding 223s work just fine with the same amount of adequate adjustment. No 204 or crimp dies to test on mine.

Just as a point of curiosity, what is your measurement to the shoulders on your fired? I know it wont be exact but it should be in the same ball park. My 223 is right around 1.560 with the hornady comparator if I remember correctly and I size back top 1.557.
Using the Hornady .330 bushing, I show a fired case to be 1.457" from base to shoulder, and I am aiming for 1.455" after resizing. All of this brass is only once fired, so I don't think that anything I'm seeing is terribly likely to be related to work-hardening.

Hmmmmmm...
 

spife7980

Full Member
Feb 10, 2017
3,369
458
83
TX
#8
Forster lock rings? Maybe the difference in diameter of one to a Redding in the slot is making a difference? But you’re screwing it down until touching so that should take up the slack of that which makes this post moot so far... can’t really put a feeler gauge under the case to artificially raise it...

Your other calibers have these problems, to me that points to the press or you somehow being the worlds worst at screwing things in.
 
Mar 16, 2017
194
3
18
Skagit Valley, WA
#9
The lock rings shouldn't have anything to do with it.

I've got a couple dies that need a significant cam-over in my Co-Ax press to work right, while other brand dies in the same caliber don't. If the OP is stopping at just a slight cam-over, try a little more, it does still have some effect. With that said, nothing wrong with shortening the die a little. Your shell holder plates in the Co-Ax might be a few thousandths too thick, but shortening the die is easier than fixing the plates.

Side note for the OP - the shoulder doesn't move forward from the neck being sized down; it moves forward from the body being sized down (in diameter) at the body/shoulder junction, pushing the shoulder forward. If you were to use a neck sizer die, you wouldn't see the shoulder move forward.
 
Sep 6, 2006
2,091
249
63
Southern California
#10
I think the shell plate idea on the coax is neat, but I converted mine to standard shell holders (Forster part) long ago. Makes things So much more flexible and quick to change.

Three new dies, all .223 case heads, and they’re not sizing enough...you have this problem with other dies like .308, Creed, etc? Can you put these dies in another press and try them? Maybe one with conventional shell holders? Too late now I suppose. The chance of you getting three different dies from two different manufacturers, and all of them having been reamed too deep is hard to believe. Something else going on. In the future, lay off the grinder. If you have legit problem dies, the manufacturer will replace them.
 
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