HC you're not visualizing this correctly. When you have a crush fit the measurement on the case will actually be longer than the bolt face to chamber shoulder datum line. That why the case is being crushed because it is too long. IOW when you crush the case in the chamber (wearing out your lugs and leading to possible chambering problems in the field), you are reducing the headspace on the case.

So if you insist on numbers then a crush fit case might be said to have a -0.002" measurement (not that you would have any tool to measure it with) and when I move the shoulder back .001" then I might have a -0.001" measurement. Then when I chamber with a SLIGHT crush fit, I am only compressing the case .001".

So I guess the deal is that you are defining PFLR as a crush fit and I am defining it as a slight crush fit. Still no "slack" so unless you can show me where I have stated this, your stating so is specious. I have repeatedly said "slight crush fit".

I can tell you that if I take a case that has been fired enough times to have a crush fit (defined as a harder to close bolt than necessary and tight enough that it could lead to galling of the bolt lugs and problems chambering in the field), measure it and size it so that my caliper says that I have moved the datum line on the case back .001", I still get a slight resistance to closing the bolt.

If you insist on having a crush fit then why set your die to move the shoulder back at all? Just keep cranking that bolt down and compressing and snugging up that case in that chamber! I know you won't do that but I am trying to illustrate that this is all a matter of degrees and you should not keep trying to put words in my posts that aren't there like "slack".

Even with your antiquated BWADT methods (I think you call them OCD or DOL or something) where you measure from the shell holder to the top of the press when sizing, you should be able to tell what measurement you are moving the shoulder back. What is it ...... .001"? Or maybe your method is not accurate enough to actually measure these things?

Hey yooz guys!

Don't make me go over there and throw a bucket of water on y'all to separate ya!

quote:

Originally posted by woods:
HC you're not visualizing this correctly. When you have a crush fit the measurement on the case will actually be longer than the bolt face to chamber shoulder datum line. That why the case is being crushed because it is too long. IOW when you crush the case in the chamber ...you are reducing the headspace on the case.

Completely AGREE 100%.

quote:

So if you insist on numbers then a crush fit case might be said to have a -0.002" measurement (not that you would have any tool to measure it with) and when I move the shoulder back .001" then I might have a -0.001" measurement. Then when I chamber with a SLIGHT crush fit, I am only compressing the case .001".

I just figured out where our communication problem is. When I mention -0.002" Headspace that does mean the Case is +0.002" LONGER than the space available inside the Chamber.

It is how "Headspace" is discussed colloquially that is causing the confusion. When someone says they have "too much Headspace" they are talking in Positive( + ) increments of measurement. For example: I have 0.002" Headspace. Which means there is 0.002" of Slack between the Case and Chamber.

So, I'm thinking in Headspace measurements where a Negative( - ) number indicates a Dimension is actually too long to fit within the Chamber.

quote:

So I guess the deal is that you are defining PFLR as a crush fit and I am defining it as a slight crush fit. Still no "slack" so unless you can show me where I have stated this, your stating so is specious. I have repeatedly said "slight crush fit".

Apparently we are in agreement.

quote:

I can tell you that if I take a case that has been fired enough times to have a crush fit (defined as a harder to close bolt than necessary and tight enough that it could lead to galling of the bolt lugs and problems chambering in the field), measure it and size it so that my caliper says that I have moved the datum line on the case back .001", I still get a slight resistance to closing the bolt.

I guess I do not have the Galling problems due to proper Cleaning and Lubrication .

But, I now understand that even though you are "Bumping Back the Shoulder", you are still not moving it enough to cause the Slack.

quote:

If you insist on having a crush fit then why set your die to move the shoulder back at all? Just keep cranking that bolt down and compressing and snugging up that case in that chamber! I know you won't do that but I am trying to illustrate that this is all a matter of degrees and you should not keep trying to put words in my posts that aren't there like "slack".

That was a misunderstanding and I accept your appology.

I need to set the P-FLR to move the Shoulder back a bit, because when the Case is actually "Resized" at the Pressure Ring(during the P-FLR Process), that causes the Case Length to "Increase" as I'm sure you know - between the Case head and Datum Line(for Woods buddy). And if I didn't move the Shoulder back a bit, I could not close the Bolt. The P-FLR insures the utmost consistency from Case to Case.

Since you are not Resizing the Pressure Ring, then your Case is only Lengthening due to the Brass not Shrinking as much as it Expanded during the firing sequence.

quote:

Even with your antiquated BWADT methods (I think you call them OCD or DOL or something) where you measure from the shell holder to the top of the press when sizing, you should be able to tell what measurement you are moving the shoulder back. What is it ...... .001"? Or maybe your method is not accurate enough to actually measure these things?

The proper P-FLR measurement is way, waaaaaaaay to Precise to be able to measure it with mear Mortal Tools.
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Anyway, I'm sure glad I got you straightened out before you got Grasshopper all in a tizzy.
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Best of luck with your Rube Goldberg Thingys.

Sheeew! Glad you sorted it out! I can't take these "disturbances in the Force"!

P.S.

I knew what both of you meant the whole time

quote:

Originally posted by Hot Core:


I need to set the P-FLR to move the Shoulder back a bit, because when the Case is actually "Resized" at the Pressure Ring(during the P-FLR Process), that causes the Case Length to "Increase" as I'm sure you know - between the Case head and Datum Line(for Woods buddy). And if I didn't move the Shoulder back a bit, I could not close the Bolt. The P-FLR insures the utmost consistency from Case to Case.

Since you are not Resizing the Pressure Ring, then your Case is only Lengthening due to the Brass not Shrinking as much as it Expanded during the firing sequence.

I guess I need to apologize again!

I do size at the pressure ring when I use the Redding Body Die. It works just like a FL die except does not touch the neck. So it sizes the case body and then when set just right pushes the shoulder back the .001".

Skywalker does get upset when the Jedi's disagree doesn't he! Guess he needs more training.

Well, I've learned something today(which might be common knowledge to EVERYONE else), I didn't realize that Redding Die touched the Pressure Ring.
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Yes, R probably needs some Water Boarding!