Forster Dies Explained

[eric32]

I got this image from the good people at Forster, i decided to post this up since i am always seeing threads talking about what is the actual difference between dies. And the myths of headspace and and small base dies and other nonsense that i read on different forums while searching for answer to random self generated questions.

Base diameter of Regular/NM dies are .467
Base diameter of SB die is .464


Please lets not turn this thread into another neck sizing vs FL sizing battle.

 

[bench]

That is good info
Now we know the amount of difference the dies make.

 

[RonAKA]

Good information. I don't see the value in the National Match option though. Is it for a specific competition where feeding ease is more important than ultimate accuracy? Also, it would seem much more economical to lap a shell holder down 0.003" rather than buy a special die.

As for the small base die, I can see that it would also be of use to those who are determined to used range brass for economy, and need to size down a case that has been fired in a sloppy chamber.

 

[eric32]

NM is for a rifle with bare minimum headspace, to get enough shoulder bump and size the case fully

 

[Liven The Dream]

Thanks.
I have a few years on me. Speer Reloading Manual had this info. in its day.
I hope a lot of disbeliever's read about SB Die. WHY.
Had a few on this Forum thinking I was Nuts.
Love seeing the printed word..

 

[John Russell]

Good information. I don't see the value in the National Match option though. Is it for a specific competition where feeding ease is more important than ultimate accuracy? Also, it would seem much more economical to lap a shell holder down 0.003" rather than buy a special die.

As for the small base die, I can see that it would also be of use to those who are determined to used range brass for economy, and need to size down a case that has been fired in a sloppy chamber.

That is because you don't know that type of shooting - there are many types of "Accuracy Shooting" besides short range benchrest. Die makers offer many types of special dies for special needs.

 

[AckleymanII]

Good post Eric!

 

[eric32]

Thanks bud!

 

[ireload2]

In your illustrations you don't know what the nominal dimension A is and you don't know the tolerance of A. If you get a die that does no work you cannot measure it and tell if it is out of tolerance or if your chamber is wonky.

I got this image from the good people at Forster, i decided to post this up since i am always seeing threads talking about what is the actual difference between dies. And the myths of headspace and and small base dies and other nonsense that i read on different forums while searching for answer to random self generated questions.View attachment 997089

Base diameter of Regular/NM dies are .467
Base diameter of SB die is .464

 

[eric32]

A is the headspace, which is set by YOU the user of the die when bumping your shoulder back.

A is also stack by the deck height of your shell holder and CAMOVER of your press.

The way to measure a case is to paint if and insert into chamber looking for shiney spots.

Look at it like this

REGULAR die doesnt bump your shoulder enough to chamber reliably. You have adjusted the die your press is maxed out and the should still wont move.

NATIONAL MATCH DIE will move the shoulder .003 if the die is set up like PREVIOUS REGULAR FL die.

 

[RonAKA]

NATIONAL MATCH DIE will move the shoulder .003 if the die is set up like PREVIOUS REGULAR FL die.

I still think it is a very expensive alternative to simply lapping 0.003" off your shell holder, or better still the exact amount you want off your shell holder based on your chamber, not some arbitrary 0.003"...

 

[Dgd6mm]

GOOD STUFF Eric.

Don Dunlap

 

[Patch700]

Good information. I don't see the value in the National Match option though. Is it for a specific competition where feeding ease is more important than ultimate accuracy?

I don't quite understand this... All of my best achievments accuracy wise have been with cases that fed or chambered easily... Hence why i opt for a case that is sized minimally in all dimensions IE: body, shoulder , base.

I have tried the necksize only game for quite some time and it led to serious tail chasing ... To each their own I suppose.

 

[SheepDog]

Just as each reloader has his own technique so every rifle and chamber has its own needs. Sizing for my old 03A3 with its huge chamber meant not sizing the body at all. If I was to size the body the case would get a vertical split through the middle of the side in as few as 3 firings. The actual headspace of the chamber is within SAAMI specs but the throat/ leade in the chamber is extremely long. Long enough to place a 180 grain bullet in the lead and chamber a case without touching the bullet. There is no way that you could get any accuracy or case life with full length sizing. Even partial full length sizing produced similar results. The best way to get accuracy from that rifle was to partially neck size, leaving enough unsized neck to center the cartridge, but enough sized to hold the bullet. My 358 is almost the exact opposite, with a fairly small chamber and lead but a normal size neck in the chamber. I have always treated it the same as my 03A3 and only partially sized the neck with excellent results. The one load I worked up for it first was producing average groups of .33" at 100 yards (sub caliber groups). I have one other rifle that has a more than generous chamber and the rest would be a good range of standard hunting rifle chambers. I get sub MOA groups from all of them without having to resort to seating depth tuning. I use the listed overall length in the manuals and tune my loads with the powder charge. It's old school but it works for me.
I am a hunter not a long range competition shooter and MOA accuracy is more than is required for my use. That does not mean I didn't go through the search for the magic "one hole group" that I believe all reloaders go through once in their reloading life. Some keep searching some decide that for their use what they have is good enough. I have never owned a target rifle - yet.

 

[eric32]

I made this thread to put out informtion about Forster dies and the difference between the Regular, NM and Small base dies.

This is not meant to start another thread that leads to neck sizing is better for me stories or how I dont FL size cause its cooler .

This is thread is about the information in my first post. If you are asking a question pertaining to Forster dies and which one to buy or Small base dies in a tight chamber. Then please go ahead.

 

[SheepDog]

I do apologize sir.

 

[eric32]

Thank you, sheep dog. I hope you found the information useful none the less.

 

[savagedasher]

Head space is a different from base size
Which is correct.
If the die is small base you should be able to adjust the head space and the standard die should do the same.
If your going to shoot a AR type gun you better use a small base die .
Happy New Year. Larry

 

[SheepDog]

All information is useful. You presented it well. I just got off track. At my age ... where were we?
The small base die is rarely needed in the AR platform. A standard full length die is generally enough to bring the case down enough for an easy fit. The only way to know for sure, unfortunately, is trial; and error.

 

[savagedasher]

All information is useful. You presented it well. I just got off track. At my age ... where were we?
The small base die is rarely needed in the AR platform. A standard full length die is generally enough to bring the case down enough for an easy fit. The only way to know for sure, unfortunately, is trial; and error.

Only takes one and you have a problem.
Happy New Year Larry