Virgin brass vs. fire formed

[woods]

Brass can be annealed as many times as you want as long as the case does not have any other problems like splits in the neck or the startings of a case head separation. IMO brass should be annealed every 3 to 4 firings for the life of the brass.

The timing of the annealing will also depend upon your sizing die. If you are using an expander then the brass is worked twice as much during the sizing operation as cases that are sized with a bushing or collet die.

Now back to hijacking the thread

 

[J E Custom]

Hey JE

A go-no-go gauge does measure the headspace on a belted case and in my explanation I said that in my measurements on headspace on the belted mags they varied from .000" to .007". That is measured from the case head to the front of the belt, or technically it is the gap between the case head and the bolt face when the belted case is seated as far forward as it will go in the chamber. The belt stops it, not the shoulder. So a go-no-go gauge will measure that headspace and it will not give you any indication of the remaining gap between the case shoulder and chamber shoulder. IOW you could easily have a headspace measurement with a go-no-go gauge of .003" and still have a head clearance measurement of .030" with a more useful gauge such as the Hornady Headspace Gauge which gives you measurements from the case head to the case shoulder, even on a belted case.

The measurement on my 30-06 was the difference between the headspace measurements taken by the Hornady on NEW cases and FULLY EXPANDED cases at the datum line. I DO NOT repeatedly full length size and DO NOT need to back off on on my sizing dies. They are set to push the shoulder back .001" from a crush fit EVERYTIME AFTER THE CASES HAVE EXPANDED. I can not however do anything about the undersize dimensions of NEW CASES since I do not have multiple hydraulic form dies and refuse to downsize cases with larger dimensions in order to preset the shoulder at a specific location on a new case. I do not make my own brass so I am stuck with what I can get just like everyone else.

The illustration was to show how a case that has a large neck variation from side to side will continue to have it's neck off center in relation to the center of the case body even after neck turning. Perhaps there are some exceptions to this, I would be happy to listen to them. I did not say that he should not neck turn anyway, just that neck turning will not solve and off center poor piece of brass. I also neck turn on new cases for several calibers.

JE, do you have a Hornady Headspace Gauge or only a go-no-go? Not trying to pick a fight so don't take this wrong, but if you do not have a Hornady Gauge then perhaps you should get one and measure the distance from the case head to the datum line on a new case for a belted mag and then measure that same distance once you fire it. Do it on a gun that your go-no-go says has a headspace between your tolerances. The excess clearance at the shoulder will surprise you and is as much a problem with the brass manufacturers as it is with the gun manufacturers.

Here are some measurements I have taken with the Hornady

rifle / new case / fully expanded case / head clearance
Mato 338 win mag / 2.0970" / 2.1240" / .027"
Sako 300 win mag / 2.2530" / 2.2735" / .0205"
Mato 300 win mag / 2.2530" / 2.2725" / .0195"
Pre-64 264 win mag / 2.109" / 2.1385" / .0295"
Win 70 264 win mag / 2.088" / 2.1290" / .0410"
Custom 6.5 rem mag / 1.768" / 1.785" / .017"

All of these guns had headspace between .000" and .007". I have since rebarreled the 338 Mato and the Win 264 and sold the pre-64 Win 264 because of their excess head clearance.

Something I noticed on my 7mm Rem Mag brass - Topic Powered by Eve Community

If gunsmiths would ream the chambers to match new brass as Saeed mentions in the above thread then the incidence of case head separations would be greatly reduced.

I understand all of the ways of measuring the head space and don't disagree with any of that
Just the amount of head space that you are willing to except !!!

I have never claimed to be all knowing But those tolerances are just not acceptable to me.

The chamber reamers that I use are SAAMI spec. and on a belted case the distance between
the front of the belt to the datum point are set by the reamer manufacture and cannot be
altered unless you specify something different.

Also brass is a material that can be altered but a chamber can't once it is finished . But why on
earth would you want the reamer made to fit the brass which by your own admission varies
a great deal.

Belted cases were introduced for a reason .They were designed to chamber under all conditions
because when hunting dangerous game one cannot afford to have a miss feed .so the concept was to have excess space in the chamber with out excess head space that would allow the
round to move forward enough to miss fire (Just as bad as not feeding) . And brass life is not
even a consideration under those conditions.

Most people that use belted cases re size only enough to chamber unless it is going to be used
for dangerous game and then full length size or even use what I call a small base die (Smaller
than SAAMI spec) to make sure it will feed and function. but the head space is still measured from the Bolt face to the back of the go head space gauge and if the bolt will close on a NO GO
gauge then It has excessive head space.

And you are right about the brass manufactures needing to make there brass to SAAMI but it is
not all ways perfect so that's the reason for fire forming and then sizing only enough to chamber
the round and extend brass life.

Maybe my standards are to high but I don't and won't own any firearm with more that .003 head
space period.

So It is just the way I see it and that's what makes the world go round.

It has still been a good debate.

Thanks
J E CUSTOM

 

[Frogman77]

In my post about my .30-06 I wasn't saying that I have .020" of head space. I was reffering to the original post about fireforming new brass.

When I use new winchester .30-06 brass it measures 1.934" to the shoulder using a sinclair bump guage. After firing once, the new measurement is 1.953-1.954". This once fired brass chambers with a crush fit and requires a little effort to close the bolt.

Now according to my reloading manuals, miniumum cartridge length to the shoulder is 1.948"

So from this information I would say that I have .005-.006" of headspace from saami specs. Maybe a little less since the once fired brass already has a crush fit to it?

Using the new winchester brass, the case was stretching too much (about .020") and I found a degradation of accuracy and also a few cases with flattening primers that with once fired brass using the same recipe had no pressure signs at all.

Sorry for the confusion. regarding the headspace issue.

 

[woods]

Well I might have to back up a little here since you bring up a good point Frogman. I am not really talking about headspace from a SAAMI standard but rather the headspace from a new case to a fired space.

So now an unbelted case could have a headspace as measured by the go-no-go of .003" and have a difference of .020" between the location of the shoulder on a new and a fired case. That would be a problem of brass manufacture and not a chamber problem.

But I would ask what would be the important dimension? To me that would be the space between the case shoulder and the chamber shoulder, whether it would be called headspace or not. Because that gap is what causes all the problems.

 

[J E Custom]

In my post about my .30-06 I wasn't saying that I have .020" of head space. I was reffering to the original post about fireforming new brass.

When I use new winchester .30-06 brass it measures 1.934" to the shoulder using a sinclair bump guage. After firing once, the new measurement is 1.953-1.954". This once fired brass chambers with a crush fit and requires a little effort to close the bolt.

Now according to my reloading manuals, miniumum cartridge length to the shoulder is 1.948"

So from this information I would say that I have .005-.006" of headspace from saami specs. Maybe a little less since the once fired brass already has a crush fit to it?

Using the new winchester brass, the case was stretching too much (about .020") and I found a degradation of accuracy and also a few cases with flattening primers that with once fired brass using the same recipe had no pressure signs at all.

Sorry for the confusion. regarding the headspace issue.

No apology required !!!

We strayed from the topic and lost site of your question.

If the chamber is a SAAMI spec. and the head space gauge is also a SAAMI gauge then you are probably correct about the head space ( .005 to .006 ) which would be max but with out a head
space gauge it is hard to say.

If you are not having any problems with your brass thinning in front of the base then you will
be OK especially the way you are re sizing. You can sacrifice one piece of brass by splitting it and measuring wall thickness or spend $35.00 and buy a GO head space gauge and use a series of shims between the gauge and the bolt face until the bolt won't close easy.

J E CUSTOM

 

[Jinx-)]

Jinx, if you would stop yelling, perhaps someone would address your question.

Sorry, I was about to toss my old brass out and I needed someone advise if its still can be of use, the Lapua brass is not the cheapest one out there, also I was thinking to try Nosler brass out, but I guess it can wait until I use-up what I have now.

 

[Bart B]

In the example where he said the firing pin pushes the case forward to the shoulder, that would not apply with a belted case. I have measured the amount of case travel in a few belted case chambers (headspace) and it varied from .000" to .007" because the belt stops forward movement. Now there is still significant space between the case shoulder and the chamber shoulder in the belted mags which is called "head clearance" and that can be as much as .030". But with the case forward movement stopped, it is not true that the firing pin pushes the case forward to contact. In a belted case the brass has to expand forward toward the shoulder.

With a belted case such that its belt stops against the belt's headspacing ridge in the chamber and there's any clearance (space?) between the case shoulder and chamber shoulder, isn't that called "shoulder clearance?"

I ask 'cause "head clearance" has typically meant the space between the bolt face and case head when the round stops moving forward in the chamber when the case headspace point stops against that point in the chamber.

Note that in the reloading industry as well as chamber reaming, chamber "head space" (either all one word or two separate ones) in SAAMI terminology for all cartridges is the distance between the bolt face and that point in a chamber that stops a case from moving forward. For rimless bottleneck cases, it's from the bolt face to a reference diameter on the chamber shoulder. For belted cases, it from the bolt fact to the ridge where the belt stops at .220" -.008" When the case stops against the headspacing point in the chamber, the distance from the bolt face to the head of the case is called "head clearance." Prefixing headspace with "case" refers to the counterpart dimension on a cartridge case; case headspace is the distance between the case head and the headspacing reference point such as the front of the belt on a belted case or head to shoulder reference on a bottleneck case.

Go ahead and change this standard to suit your own lingo about firearms if it suits your fancy, but doing so will end up confusing newcomers to the games.