What does headspace do for a rifle, round, die setup, case stretch and head separatio

[Pond, James Pond]

There seems to be a pronounced difference of opinion.

I certainly don't know who is right, but I will say this.

It is unpleasant to acknowledge that we are wrong on a point, especially when we have believed it strongly.

However, I would encourage all to consider what the others are saying, all the while remembering that all this is ultimately about making shooting more effective, more efficient and safer.

Surely, reasons worthy of a bit of self-examination, no?

[Metal god]

Heres what happens when you size cases 7 to 10 thou shorter then your chambers headspace . Thought you might like to see what your trying to avoid

The cases on the left were reloaded 3 times the cases on the right were loaded 5 times after I learned how to size my cases better .



Click for closer look here
http://imageshack.com/a/img62/2971/mjcn.jpg

[Pond, James Pond]

What did the damage?

Looks like pliers.

[Metal god]

Sorry , I should have explained the cases on the left a little better . You should be looking at the head separation toward the bottom of the case . I did in fact crush those with Chanel locks because of the head separation that occurred .If a case is damaged I was told and believe it's a good idea to destroy it so you don't accidentally load it again and cause huge problems to your gun and or your self . You can see the crack in the case just above the head area do to the case stretching to much after each firing because I sized the cases to small by .007 to .010. After the third time I fired those cases many of them cracked open or looked like the one on the far left . It's not cracked but it would fail for sure the next time it was fired .

Not sure if you did but if you click on the link you can get a very close up view of the pic by clicking on a area of the pic you want to enlarge

[Pond, James Pond]

You should be looking at the head separation toward the bottom of the case . I did in fact crush those with Chanel locks because of the head separation that occurred .If a case is damaged I was told and believe it's a good idea to destroy it so you don't accidentally load it again and cause huge problems to your gun and or your self .

So that is what case separation looks like!

I agree with your handling of damaged cases. I do the same.

[HiBC]

Now,Mr Pond,that you see the pix thoughtfully provided by Metal...

I suggest you find a paperclip.Straighten it out.Then use a pliers to bend a 2 to 3 mm 90 deg bend at the end,so it is "L" shaped....like a small allen wrench with a very short leg.

Now,do you see where the separation appears on the brass?It begins on the inside,a "stretch ring",almost like an o-ring groove inside the case.

You may use your new paper clip tool as a probe to detect this stretch ring.Just stroke it in and out at the approximate depth the crack appears.

You will know when you find one.

By using this tool you can sort out the weakened brass before failure.

I suggest you cut one open and observe the ring.

The good news,if you practice what you have learned via this thread,you will gain many reloadings from your brass,you will not have to deal with brass failure,and you have a much better understanding about your initial question.

Good job,Us!!

[Pond, James Pond]

You may use your new paper clip tool as a probe to detect this stretch ring.Just stroke it in and out at the approximate depth the crack appears.

Waaaaay ahead of you!!

I bought a set of O-ring removers a while back especially for that which are steel, bent at various angles with sharp tips!!

I also just tried my headspace adaptor and the two cases I have tried (43.1gr and 45.2gr) from each end of my charge range measured 40.61mm to the point of measurement on the shoulder.

It seems the hot ones did not stretch any more than the light ones.

[Pond, James Pond]

A further thought.

I've just got off the phone to my reloading tools supplier and they told me about a Forster shoulder resetting die, that only does the neck and shoulders (sounds like a therapy treatment), but leaves the fire-formed walls the same.

Can my Lee full-length die be as effective, or does this Forster model have a supreme advantage?

Would its gains be insignificant to someone of my shooting skill?

[F. Guffey]

I've just got off the phone to my reloading tools supplier and they told me about a Forster shoulder resetting die, that only does the neck and shoulders (sounds like a therapy treatment), but leaves the fire-formed walls the same.

I believe it would be appropriate by this time to suggest "question all the answers". Reloaders were led to believe it was possible to have a bump die and a body die, it could have been a body/bump die. Problem with the understanding of bumping the shoulder, the shoulder can not be bumped without body support. Bumping the shoulder without case body support causes the case to bulge, it should not take a rleoader long to figure if the case bulges between the shoulder and case head the case will require sizing when the bolt is closed. Something else a reloader should know, when the case body is sized down the shoulder moves forward causing more difficulty/resistance to bolt closing.

Point? The body/bump dies were full length sizer dies with loose necks, nothing new 'for me', I have 30/06 dies that fit the 270 W and are loose at the neck. For the 30/06 I have the 8mm06 dies, 308 W dies for 7mm08.

I can not bump the shoulder without the die contacting the case body, the die body supports the case body. When I size a case the body of the case is reduced in diameter, when that happens the shoulder moves forward, moving the shoulder forward increases the length of the case from the shoulder to the head of the case.

F. Guffey

[Bart B.]

Problem with the understanding of bumping the shoulder, the shoulder can not be bumped without body support. Bumping the shoulder without case body support causes the case to bulge...

The giant bronze gong at the back of the stage just got smacked with that long, heavy mallet swung by a good lookin girl.......

People have been using dies with bushings with different neck diameters and shoulder angles to bump fired case shoulders back a few thousandths for decades. Benchresters did this for years. All without any body support and no case body reshaping.

I tried it myself and verified that my .308 Win. cases, even those weighing only 150 grains having the thinnest body walls of any, didn't buckle their shoulders with the Neil Jones bushing die. Cases so bumped dropped easily into Wilson shell holders for their trimmer to the same depth after bumping as before. Evidence to me their body dimensions were not altered.

Try using a bit of good case lube on case necks and shoulders and the case body will not be mishapen at all.

Such dies were never intended to set fired case shoulders back more than a few thousandts; probably 10 at the extreme limits of sensibility.

[F. Guffey]

Such dies were never intended to set fired case shoulders back more than a few thousandths; probably 10 at the extreme limits of sensibility.

All the years? In the beginning reloaders understood 'bump', it makes the reloader of today sound like they have a good grip on what is happening like "I bump my shoulder back .001 or .002".

I have presses that are bump presses and I have presses that do not bump. I can not bump the shoulder of a case back without case body support. Again, I ask if there is anyone that has scribed the case body/shoulder juncture.

It is impossible to move (bump) the shoulder back as in shorten the case between the shoulder of the case and case head without case body support.
On a case that has been fired and already fits the chamber?

F. Guffey

probably 10 at the extreme limits of sensibility

.010"? You are saying the shoulder will slide and glide past the shoulder of the die and neck down the neck at the same time when in reality .010" is some serious sizing

Reloaders are cautioned against neck sizing, the neck sizing die does not contact the shoulder of the case. Then there is that small effort used for crimp, the smallest amount of over crimp upsets the shoulder and case body/shoulder juncture, I find it impossible to bump the shoulder and size the neck without case body support.

[Bart B.]

Yes.

The sloped part will move towards the case head shortening the distance between these two points. The brass at any given point will remain there. Measurements are made from a point on that slope, or shoulder. Not some finite particle of brass that pretty much stays the same distance from the case head.

It's the slope that moves; exactly the opposite of a wave on the beach. That wave slope moves towards the beach but the water in it pretty much stays in one place. That slope on a bottleneck case is its shoulder regardless of how it gets moved around by the shoulder in a sizing die.

When I make a .30-.338 case full length sizing a .300 Win Mag case in its die, the brass in its shoulder fairly well stays in the same place. But the 25 degree slope moves back about 1/7th inch; .140" on my measurements. A point that was 1/16th inch up the shoulder from the neck on the original case ends up about 1/16th inch out on the neck from the new shoulder position.

[F. Guffey]

Yes.

The sloped part will move towards the case head shortening the distance between these two points. The brass at any given point will remain there. Measurements are made from a point on that slope, or shoulder. Not some finite particle of brass that pretty much stays the same distance from the case head.

Without case body support

The sloped part will move towards the case head shortening the distance between these two points.

And now you are telling me the case body compresses and while it is being compressed it does not require case body support.

I am one of the few that make gages that make measurements from a point on the slope.

I have turned cases into accordion looking bellows without effort and without case body support.

F. Guffey

[Bart B.]

You have turned cases into accordion looking bellows without effort and without case body support?

Next time use a little bit of case lube on all the right places. And don't move the shoulder very much. That's what people do and don't crumple case bodies.

If you don't think that's fair, then go play some other game with rules you can get along with and operate within.

[F. Guffey]

And don't move the shoulder very much.

Very much? You have gone from .010" to 'not very much'. Bart B., it is impossible to bump a shoulder without case body support. I know, they labeled the dies 'bump' then they labeled a die 'body die' and I said that is impossible. then I said I have sizing dies with loose necks that do the same thing, some better than others because there was more difference in the neck diameters.

Reloaders were under the illusion the body of the case was sized and the shoulder was not touched, and I said "That is impossible". I insisted if the body was sized the shoulder had to contact the shoulder of the die, then finally they said it was a die that sized the case body and shoulder and the case neck would require sizing after the body and shoulder was sized. All of that in an effort to avoid pulling the neck sizer plug back through the neck.

F. Guffey

You have turned cases into accordion looking bellows without effort and without case body support?

Bart B., the case does not hesitate, as soon as the die touches the shoulder of the case without support the case starts to collapse.

A very disciplined shooter/collector/reloader and builder of very fine rifles brought me bits and pieces of dies made back in the '50s and earl '60s, they did not work. He wanted to know why. He thought he had found the beginning of 'bump dies' I explained to him why the dies did not work. He asked if I had any interest in finishing the dies, and I said "no".

F. Guffey

[Bart B.]

What ever. . . . . . .

[Pond, James Pond]

I feel like I am in a Harold Pinter play.....

I am going to stick to my Lee full length sizing die, if only because I can't afford another die right now selling for £70 (~$90?) and I have yet to try my hand at bumping, shoving, coercing, cajoling or hypnotising the shoulder anywhere as yet.

Once I know I am able to do it and have played around, then I can think about upgrading.

@HiBC
I ran my sharp steel pin up the inside of the case: nothing but smooth metal in both the "hot" loads. Looks like I am still safely some way away from case-head separation.

[Brian Pfleuger]

Originally Posted by Pond

A further thought.

I've just got off the phone to my reloading tools supplier and they told me about a Forster shoulder resetting die, that only does the neck and shoulders (sounds like a therapy treatment), but leaves the fire-formed walls the same.

Can my Lee full-length die be as effective, or does this Forster model have a supreme advantage?

Would its gains be insignificant to someone of my shooting skill?

I've never used the Forester (or even heard of it until now) but the best method is (generally considered) to slightly size the walls as well. Ideally, only a thou or two. Most factory dies size to SAAMI minimum or near.

You can use your Lee FL die, or get the Forester one (I'd like to hear how you like it) or if Redding dies are available to you they make a body die that can be used in conjunction with the Lee collet die. I get excellent results with that combination.

[Magnum Wheel Man]

BTW... POND... I keep a stainless dentist pick on my bench for checking for web separation... it works quite well... I started doing that when I was heavily reloading 5.7 X 28, as they stretch nearly an 1/8" per firing...

I just bought 500 once fired range pick up Remington headstamp 223 cases... I found 2 of them that had similar lines in them, to the cases pictured ( my 1st thought, was that the chamber was damaged... but I only found 2 in 500, so that was not likely... I used my pick to check the insides, & they were clean ( smooth, no crack starting ) so I have to assume they were factory defects in the cases

[HJ857]

I feel like I am in a Harold Pinter play.....

Yep, you can just put them in your ignore list so you don't have to read their posts.