Same brass reloaded X times...

[Bart B.]

Originally Posted by F. Guffey

Too bad reloaders never learned to measure the diameter of the case head. I understand it must be complicated because the case head diameter must be measured before and again after. And then there are all of those + & - things, variables etc. etc.

Before the Internet: Case head expansion with factory ammo was .00025". Today that means nothing but back before the Internet a reloader could determine if his loads were close to factory loads.

I have fired cases loaded once that had .010" case head expansion. Forget the primer pocket, the flash hole and the thickness of the case head from the cup above the web to the case head. When the case head was crushed and the case body was locked to the chamber the case was well on its way to suffering case head separation.

F. Guffey

That .00025" standard is a good example of ignorance and a rubber ruler. It cannot be meaningful across all cartridges with a wide range of pressure specs, 20 to 30 thousand psi, for example. Would be nice to have Brass Units of Pressure (BUP) but that has not moved past the UWAG stage; Unscientific Wild Ass Guess.

Measuring case head expansion is the same as measuring copper crusher disk thickness. Without a tarage table for each lot of cases so the difference in thickness could be related to a reference, case head expansion amount is meaningless. One standard does not fit all cases, some lots are softer than others. Exactly like crusher discs. And the table is not linear in shape. To say nothing about the wide range of primer pocket to extractor groove dimensions from 222 Rem to a 505 Gibbs.

[F. Guffey]

That .00025" standard is a good example of ignorance and a rubber ruler. It cannot be meaningful across all cartridges with a wide range of pressure specs, 20 to 30 thousand psi, for example.

If you can not do it, you can not do it. It is not my job to convince anyone it is not possible. For many years I have said I wish there was something in the chamber when the trigger was pulled. My cases do not have head space and when I pull the trigger I have something in the chamber; I have a case in the chamber.

F. Guffey

[Metal god]

Hounddawg those are the OP’s cases , I did a screen grab of one of his pics .

Bart , ok but none of mine have that sharp and distinct a line .

[Bart B.]

Originally Posted by Metal god

Bart , ok but none of mine have that sharp and distinct a line .

Do you want a list of all the reasons all cases will not have their pressure rings appear the same?

Interesting article on pressure estimates:

http://www.hodgdonreloading.com/relo...-rifle-reloads.

Note the 270 Win has the same peak pressure specs as some magnum cartridges. 65,000 psi. And all the numbers are much higher than the .00025" Guffey uses as his standard.

[Metal god]

Do you want a list of all the reasons all cases will not have their pressure rings appear the same?

No not all , just a list of the reasons you see them look that distinct and some pics of the ones you say you have that look the same will be good enough

All my cases with many reloads look that way.

since all your cases look like that a pic should not be to difficulty to show

[Bart B.]

Originally Posted by Metal god

No not all , just a list of the reasons you see them look that distinct and some pics of the ones you say you have that look the same will be good enough

since all your cases look like that a pic should not be to difficulty to show

Ain't got pictures but here's why they differ:

Case wall thickness.
Chamber surface texture.
Case metallurgy.
Ambient light colors and how it reflects off cases; pictures vs. actual viewing the case.
How much the case body slid back against the chamber wall while pressed against it.
Chamber pressure curve shape.

Didn't mean looking "exactly" the same. Just similar.

https://thefiringline.com/forums/att...5&d=1561234796

[Metal god]

Assuming that's one case turned 180* . That looks to me a case fired in a chamber that has an out of square bolt to the chamber axis ?? If so it is actually stretched more on one side then the other . Is that the ring we see there ? As you define pressure ring , the "pressure ring " should not look like casehead stretch when casehead separation is about to happens ??

They have two different appearances and your pic looks like it stretched longways on one side like cases do all the way around with near max pressures and to much head clearance ??

[Bart B.]

That case is one out of a couple dozen or more that had the same bulge height on one side, the other few hundred of the same Rem 308 BR lot had the same bulge but all 360 degrees around the case. All were max loads 45. 3 grains of IMR4895 over a Rem 7.5 primer with a Sierra 155 gr. bullet. Head clearance on all those FL resized 2x fired cases was about .001 inch.

Those single side bulges were all at the thinnest part of the case wall. All the rest had very uniform wall thickness and a bit lower pressure ring height all around the case.

The popular myth about cases expanding away from where their body may rest against the chamber body is alive and well. Cases are exactly like the car tire syndrome; put enough pressure in them and the flat spot on the road they contact moves out with the rest forming a very perfectly round tire

[Metal god]

Oh ok i get it , that makes sense .

[hdbiker]

I find a paper clip straightened with about 1/8 inch at one end bent at 90 degrees and rubbed up and down inside the case will reveal possible head separations. visible ring just above case head outside the case also an indicator. hdbiker

[Bart B.]

Originally Posted by hdbiker

visible ring just above case head outside the case also an indicator.

All cases get that "ring" near their head on first firing.

[ninosdemente]

When I first started loading 30-06, that ring appeared on the brass as well. They were reloaded after firing factory bought ammo.

[F. Guffey]

I find a paper clip straightened with about 1/8 inch at one end bent at 90 degrees and rubbed up and down inside the case will reveal possible head separations. visible ring just above case head outside the case also an indicator.

There is case head protrusion and unsupported case head, I have suggested reloaders reverse the case and then place the case head into the die with the big end first. that is a problem because it is one of those techniques that require the reloader to remove their hands from the key board, and then there is the rational/reason for checking head case diameter.

F. Guffey

[ninosdemente]

So I cut one of the brass in half and while inspecting doesn't look there is anything. Will cut another 2 to see if there is anything different.

http://www.mentegraphics.com/pictures/114.jpg
http://www.mentegraphics.com/pictures/115.jpg

The inner mark on the top of the brass, that was me when using a grinder.

I also tried the paper clip and didn't feel anything when running it up and down inside the case. Tried it on 8 pieces of brass.

[F. Guffey]

So I cut one of the brass in half and while inspecting doesn't look there is anything. Will cut another 2 to see if there is anything different.

Again, my favorite cases are cases that will not allow the bolt to close.

Again: I have purchased thousands of cases from firing ranges, I purchased the cases hoping I could find cases that were fired in trashy old chambers. Other reloaders have cases with head space, not me; my cases do not have head space. I off set the length of the chamber with the length of the case from the shoulder to the case head. I am the fan of 'case clearance'.

I am also the fan of having nothing between the case and chamber but air, not just any air, I want clean air. cases are embeddable, almost anything that is between the case and chamber will embed into the case when fired. And we have the slide and glide shooters, they lather up the chamber with grease and they lather the case and bullet with grease, I don't, I want my case to lock onto the chamber when fired.

When I was purchasing cases from ranges I measured the length of the case from the shoulder to the case head. Most of the cases I purchased were go-gage length from the shoulder to the case head + a couple of thousandths. And then there were those cases that were no go-gage length, those were my favorite. With those cases I did not have to haul my rifles to the firing range to determine the length of the chamber. And then there were those cases with long case bodies from the shoulder to the case head. It always help to know what chamber they were fired in.

F. Guffey

[RaySendero]

ninosdemente wrote:

So I cut one of the brass in half and while inspecting doesn't look there is anything.

.

Good pic, Thx

[Bart B.]

Guffey says:

Again, my favorite cases are cases that will not allow the bolt to close.

Then the case shoulder, one or two body points and head are touching the chamber limits.

I am also the fan of having nothing between the case and chamber but air, not just any air, I want clean air.

Then the case cannot touch the chamber anywhere; it has to somehow be suspended in space. And all the airborne particulates of previously burned powder and primer have to be evacuated.

Physically impossible to have both

[Metal god]

Physically impossible to have both

Not if there is no context . If I were to be sizing a case I think the first quote would be reasonable and after sizing the second quote would be reasonable . How ever I have him on my ignore list so I don't know the context . This is how I can infer both being possible because I have no context to judge the quotes lol .

[Unclenick]

Ninosdemente,

I don't see any issue with those cases either. I think the comment that you are seeing a ding caused by the loading or ejection process is right. Lots of guns spin a case on ejection and they can run into something. Look all over the receiver for a brass-colored mark where it's hitting.

[Metal god]

I don't see any issue with those cases either.

Yep me either , which means my observation about those rings was wrong poor little MG haha

[ninosdemente]

So does that mean I can still use them then? If so, I will F/L them. Thanks guys.

[Bart B.]

Yes.

[cw308]

If the cases were cleaned with 0000 steel wool and the scratch disappeared wouldn't it show the problem was from a surface scratch instead of a stretch or thinning problem . The paper clip is a easy fix why not try the easy tests first . Not everything has to be so complicated.

[F. Guffey]

If the cases were cleaned with 0000 steel wool and the scratch disappeared wouldn't it show the problem was from a surface scratch instead of a stretch or thinning problem . The paper clip is a easy fix why not try the easy tests first . Not everything has to be so complicated.

I know of no one, with one exception, on the Internet that cleans cases with steel wool. Out side of the Internet I have a neighbor that uses steel wool when cleaning cases with steel wool for a fast turn around meaning it is faster that tumbling 20 cases with steel wool than it is to tumble 20 cases.

And then? There are the worst of cases, the worst of cases require ever thing including the kitchen sink. I use different methods and or techniques, it depends on the number of cases, there was that day I started on 1,400 cases I purchased for $14.00. The only reason the cases were available at a penny each was no one wanted to spent 4 days tumbling.

NOW; if those cases were difficult to find cases and there were only 20 with matching head stamps I would have 'finished' with steel wool. And then there is that thing about making tools for steel wool.

F. Guffey

[Don Fischer]

The science of ammo reloading. Ain't it great? Not sure I have any clue what this thread is about any more!