No cam sizing.

[AJC1]

I have found my second 308 sizing die in a short period of time that will way oversize if I touch the shell holder. My forester national match die has to be backed off and I see a gap between the shell holder and die. There is no datum line on the Sami drawings and I dont have either of the absolute measurements. If I had a go gauge or a rcbs precision mic I would compare those numbers. Using the hornaday tool I get 1.625 or 1.626 but with no standard its really meaningless. My chamber is 1.628 ish so I'm getting the sizing I want and need. Is their a way to find sammi spec other than those two, not worried just curious.

 

[jmorris]

How do you know it way over sizes?

My chamber is 1.628 ish so I'm getting the sizing I want and need. Is their a way to find sammi spec other than those two, not worried just curious.

What difference would it make knowing what range would be within SAAMI specs if that is outside where you want to be with the chamber you are loading for?

Sounds like you are looking for this.



You can find it and others here.
https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[JJFitch]

I think proper sizing is a much an art as it is science. I had the opposite problem with Hornady dies for .223 Rem. Following the die instructions left cases that were a about .001 oversize at the base but within SAAMI specs! I have to "kiss" the shell holder plus 1/4 turn!! I figure this is a symptom of the sizing ring location and the "tight" chamber in one rifle!

(Corrected to remove "carbide sizing ring")

Smiles,

 

[AJC1]

How do you know it way over sizes?



What difference would it make knowing what range would be within SAAMI specs if that is outside where you want to be with the chamber you are loading for?

Sounds like you are looking for this.

View attachment 993455

You can find it and others here.
https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

There are way more measurements on that drawing than in my book. I thought Lyman used sammi drawings but I guess they "cleaned them up"

 

[JFrank]

When you say way oversize, are you speaking of base to datum or case shoulder junction or .200 datum or all ?
How many thousand gap between the shell holder and the die base?

 

[Jim Watson]

I figure this is a symptom of the carbide ring location and the "tight" chamber in one rifle!

I didn't know Hornady made carbide rifle dies.

 

[AJC1]

When you say way oversize, are you speaking of base to datum or case shoulder junction or .200 datum or all ?
How many thousand gap between the shell holder and the die base?

I'll measure next time. The sizing I watching is the shoulder. My consern is that the base is not getting sized because it doesn't enter the die.

 

[Jim Watson]

But will it enter the chamber?

 

[JFrank]

Great

 

[FROGO207]

The base should not expand at the point the sizing die stops. That is in the thicker area of the web. As long as the sized brass fits your chamber and bolt closes you have resized enough to work. If not camming over the brass tension being different in various brands and/or batches will produce slight variations in spring back that affect shoulder length.

 

[Varminterror]

If it fits, it ships. SAAMI specs are irrelevant, your chamber is what matters.

 

[NMexJim]

I've shoulder bumped in 22-.250, .243, .25-06, .270 .280, 28 Nozler, and .308. I've never had any size problems at the case head for the reasons mentioned above.

I do mic rim and head occasionally especially when loads are hottish, but I don't worry about it much as I've not had issues there. Records and notes are a great invention especially if you start when the chamber is new.

If you do experience problems, then that's a pretty good sign that your load has been a tad too hot. I like case gauges. Makes the process quick, easy, and gives peace of mind.

If your accuracy load is that hot, then I suppose a fully seated die or a specialty die like a bushing dies might be in order - kinda necessary for long range anyway.

 

[AJC1]

I've shoulder bumped in 22-.250, .243, .25-06, .270 .280, 28 Nozler, and .308. I've never had any size problems at the case head for the reasons mentioned above.

I do mic rim and head occasionally especially when loads are hottish, but I don't worry about it much as I've not had issues there. Records and notes are a great invention especially if you start when the chamber is new.

If you do experience problems, then that's a pretty good sign that your load has been a tad too hot. I like case gauges. Makes the process quick, easy, and gives peace of mind.

If your accuracy load is that hot, then I suppose a fully seated die or a specialty die like a bushing dies might be in order - kinda necessary for long range anyway.

Running a lyman case guage and the fall right in and out. Being that these are 20k ish psi loads hot they are not.

 

[Jim Watson]

You are loading to 20,000 psi in .308? Cast bullets?

 

[jmorris]

How many thousand gap between the shell holder and the die base?

As I have needed to modify shell holders or dies before, from more than one manufacturer, I often have wondered the difference in tolerance between the portion of the shell holder that contacts the base of the case and the portion of the shell holder that would contact the bottom of the die.

As well as the case here where the OP is using a Forster die in a press that uses a shell holder vs the Forster co-ax that does not.

 

[AJC1]

As I have needed to modify shell holders or dies before, from more than one manufacturer, I often have wondered the difference in tolerance between the portion of the shell holder that contacts the base of the case and the portion of the shell holder that would contact the bottom of the die.

As well as the case here where the OP is using a Forster die in a press that uses a shell holder vs the Forster co-ax that does not.

Interesting observation both dies are from companies that do not use standard shell holders. I missed that at first.

 

[jmorris]

Just something to keep in mind. I think from the portion where the case sits to the top where a die would contact, is going to be around .025” but just measuring one shell holder, a 550 shell plate, 650 shell plate and Forster co-ax I got a max of .028” and a minimum of .022”.

 

[AJC1]

Just something to keep in mind. I think from the portion where the case sits to the top where a die would contact, is going to be around .025” but just measuring one shell holder, a 550 shell plate, 650 shell plate and Forster co-ax I got a max of .028” and a minimum of .022”.

On a progressive you would have flex right? On the coax I think that's a non issue.

 

[AJC1]

I think proper sizing is a much an art as it is science. I had the opposite problem with Hornady dies for .223 Rem. Following the die instructions left cases that were a about .001 oversize at the base but within SAAMI specs! I have to "kiss" the shell holder plus 1/4 turn!! I figure this is a symptom of the carbide ring location and the "tight" chamber in one rifle!

Smiles,

This is most often the case I hear about and the reason for my surprise. People talking about lapping shell holders and grinding or cutting down dies is common enough.

 

[jmorris]

On a progressive you would have flex right? On the coax I think that's a non issue.

Everything moves as loads are applied, some things less than others. This too can be measured. Easiest way is to run a die down to contact a shell holder then put in a case and go ram down to the point the linkage is bottomed out. Now what size feeler gauge can you fit between the shell holder and die?

On a good press with say a well lubed pistol case or even a rifle case with great lube and it doesn’t require much movement/force, it might be smaller than a .001 feeler gauge.

You could also just mount an indicator to the base of the press (not bench or you will be measuring that movement too) and go off the top. You will see how much force flexes the frame, lower the die to contact and then some fraction of a turn further.



If you think your press doesn’t move at all, under any load, you just don’t have an indicator with enough resolution to see it but they are available.




That’s not to mean the movement is consequential but it’s there.

 

[Bfh_auto]

If it fits, it ships. SAAMI specs are irrelevant, your chamber is what matters.

LoL. I'm going to remember this one.
I agree totally.

 

[JJFitch]

I didn't know Hornady made carbide rifle dies.

I misspoke! Their straight wall cases have the Titanium Nitride ring. The first set of .223 dies I bought in 1997 stripped copper during resizing. When speaking to their tech guy to get this sorted out he said there is a sizing ring in their dies. These were contracted out and some weren't finished correctly. He sent me a new set of Dies! Now after looking at the die instructions and their reloading manual I don't know what ring or if there is even a sizing ring in their bottle neck rifle dies!

Sorry for the misinformation!

JF

 

[JFrank]

As I have needed to modify shell holders or dies before, from more than one manufacturer, I often have wondered the difference in tolerance between the portion of the shell holder that contacts the base of the case and the portion of the shell holder that would contact the bottom of the die.

As well as the case here where the OP is using a Forster die in a press that uses a shell holder vs the Forster co-ax that does not.

Ill go out on a limb and suggest Forester designed the NM die with a few thousand off the bottom and once measured the body will have minimum reduction as well.
Reminds me of Redding's type S ( speedy Gonzalez) die with .015 off the bottom.