What causes this?

[David LaPell]

I found of few .44 Magnum cases that seem to have a crease in the base of the shell. There is no separation, but there is a fine line that you can easily see and feel. It appears on several cases that I found, Remington, Federal, and Norma. I don't plan on using these, I am just curious as to what caused this, I have never seen anything like it before.

 

[bmcgilvray]

Looks like a incipient head separation in the photograph. The cases also appears to be reloaded quite a few times. It's just "plum wore out."

I have to wonder though if it was fired in a springy rifle action a few times. I've not personally ever experience such head separations in revolvers but have in .303 SMLEs and some old Winchester lever action rifles.

Hey David,

I've been enjoying the de Toqueville quote you've had up recently. Very timely, even after 180 years.

 

[Alk8944]

Originally posted by bmcgilvray:
Looks like a incipient head separation in the photograph. The cases also appears to be reloaded quite a few times. It's just "plum wore out."

Ain't no such thing. It is nothing more that a straght wall pistol case that has been sized too close to the base with a carbide sizer die. If you try to size too close to the head then the heavier wall in front of the web is compressed, this area is too strong to be re-expanded when the cartridge is fired again.

Old style steel sizing dies are two diameter. Carbide dies use a ring that of necessity needs to be small enough to size the case mouth sufficiently to hold a bullet. This diameter is too small to size full lenght in, even though many do. What you see with this case is the result.

 

[Gun 4 Fun]

I agree with the above post for the most part, with the exception of the part about sizing too close to the base. I resize all my pistol cases as far down as I can run them into the die. I never get that ring. All of my cases, even those fired in a Ruger with oversized chambers in .45 Colt, that normally have an exaggerated bulge in that area, will fit in any other gun once resized in my dies. I can get upwards of 30 reloads with my brass, and full power loads at that, using my dies set up to size all the way down.

The ring was caused by a poorly ground or manufactured carbide ring in the die. It was ground too much undersized, with the leading edge left too square or sharp, and that is the result. I would send it back to the manufacturer if the die was mine.

I realize that you said that you found these cases however.

 

[Jellybean]

I agree with bmc, I had a friend that liked to shoot his .357 Puma at full speed, plus a little more. Most of his cases looked just like that on the first firing. The rest tore in two on extraction. If it is, you might be able to tell by looking down inside the case for a groove at the web.

 

[Paul5388]

The ring was caused by a poorly ground or manufactured carbide ring in the die. It was ground too much undersized, with the leading edge left too square or sharp, and that is the result. I would send it back to the manufacturer if the die was mine.

Yep, I had to send a 7mm STW sizing die back for a similar problem. Of course, it probably wouldn't look quite as bad if it had been resized all the way as close to the rim as possible.

However, if you look at the bright shiny spot, you'll see the case separation/crack in progress.

 

[Gun 4 Fun]

An incipient case head seperation won't leave a ring, or sharp edge like that on the outside of the brass. It will be on the inside of the case, and instead of a ledge like that, it will actually be a shallow groove where the brass has been stretched too thin. The groove is on the inside, because the pressure upon firing the round, forces the brass against the wall of the chamber, keeping the outside smooth.

It will leave a visible stretch mark, indentified by a ring on the outside of the case, that is brighter than the surrounding metal due to the stretching.

I agree with Paul5388 that there is a visible seperation about to occur, but it is due to the metal being worked too thin by the undersized die. I bet if you measure that case it is well over maximum trim to length.

 

[bmcgilvray]

Hi again David;

Did you happen to attempt to "feel" the inside of the case with a pick made from a paper clip with a very short crook on its end?

 

[shovelwrench]

Originally posted by bmcgilvray:
Hi again David;

Did you happen to attempt to "feel" the inside of the case with a pick made from a paper clip with a very short crook on its end?

+1

If it was fired, the sizing marks would be near indistinguishable from the rest of the case.. something is goin on here.

Lets see the primer of these case. How many times were they reloaded?

 

[David LaPell]

I have no way of knowing how many times these cases were reloaded, they came with a bunch of stuff. They were in a little case that said .44 rifle, and that's all that I know about them.

 

[Alk8944]

The ring was caused by a poorly ground or manufactured carbide ring in the die. It was ground too much undersized, with the leading edge left too square or sharp, and that is the result.

I would disagree with this observation only to the degree that there is nothing wrong with the die, it was just made in a time when the philosophy of the die makers was different than it is now. Earlier Carbide dies all used size rings that were bored as a cylinder with a fairly tight radiius at the entrance. They all would do this in the 60s, 70s, and into the 80s when production methods and philosophy changed and they began making the size rings with a slight taper and more generous radiius to prevent this sort of damage. If you look at a case deeply sized in a newer die it will almost look like a slight botttleneck with a very sloping shoulder in the area where the ring stopped.

If the guy had set the die to size only so far as the case actually expanded, instead of trying to bump the die with the shellholder, this wouldn't have happened. The old style die just needs to be used a little differently.

 

[Paul5388]

The 7mm STW dies I cited certainly weren't carbide and they also weren't more than 1 year old.

The brass I was sizing was about .003" oversize from a custom chamber and it would shave a small ring of brass off of the case when the die reached the extractor groove.

When the die got back from the manufacturer, it didn't shave brass any more.

When I went out and measured some military .38 Special that had been sized with a carbide die, I found .3732" just forward of the head of the case. Closer to the mouth, it was .3727". I really don't consider .0005" much of a taper.

 

[bmcgilvray]

The photo is slightly out of focus but still provides plenty of detail. I simply don't see the bright ring as a "ledge" or a sharp edge but only as a bright ring.

The photo also reveals a case that has had dents "ironed out" through subsequent resizing and firing, and the mouth appears to have been crimped heavily, fired and sized several times as well. It was also likely tarnished and was cleaned in some manner besides tumbling sometime prior to its last use.

I dug around in a small drawer on my reloading bench that holds many different types cartridge case anomalies and failures to come up with a .30-40 case that appears the same as the .44 Magnum case in the above photo, and the ring may be felt with the fingernail. I know this case was fired in a Winchester Model 1895 rifle I used to have and it has an incipient case head separation. I also have other cases that give examples of the same issue.

While such a failure is more decisively discerned by use of a pick on the inside of a case it may also be felt with a fingernail on the case exterior.

I never had cases appear this way though full-length sized in 1970s RCBS carbide dies. I don't however adjust the dies to bump the shell holder, preferring to back them off a quarter turn.

It very well could have been fired in a rifle with an action that had head space problems or some sort of fault in its lock-up that, in effect, gave it head space problems upon firing. A springy lever action or a rear-locking bolt action(or even a single shot made on the order of the H&R Handy Rifle), a hot hand load, in a well-used cartridge case could easily yield such a result.

 

[Gun 4 Fun]

originally posted by Alk8944

I would disagree with this observation only to the degree that there is nothing wrong with the die, it was just made in a time when the philosophy of the die makers was different than it is now.

I posted that, because I have seen it on cases sized in newly manufactured dies. I think that you may have a valid point about the older dies though.

If you look about 40% of the way up from the head of the case, you will see another, though fainter ring like the one at the head of the case. That is definately a die problem. The line I am speaking about is too far back from the mouth of the case to be a factory knurling like on some .45 ACP, and .45 Colt cases, as well as others still made today.

 

[bmcgilvray]

I saw that second ring but attributed it to a scratch rather than a die problem. I've not seen a .44 Magnum case with a cannelure so don't think that's what it is.

 

[Gun 4 Fun]

bmcgilvray

I would agree with you, except that the ring looks clearly to me like a ridge on the outside of the case when I enlarge and magnify the picture. Also, the ring if it were a case seperation about to happen, should be forwards toward the case mouth another 3/32" to 1/8", right where the case swells out at the start of the bulge.

The line that is there is just about exactly at the bottom of the primer pocket, and is still below the point on the case where the brass thins out going into the sidewall, where a seperation should occur. In hundreds of thousands of reloads, I have only had seperations either start to, or occur a few times. Each one has been farther up the sidewall a bit.

If you look at the picture closely, you can see at what appears to be about 1/8" above, or to the right of the line, the start of an actual seperation. The tiny crack is almost exactly halfway from top to bottom in the photo, next to the small light streak. Under magnification it is quite easy to see. That is also the point I was describing on my own cases that have seperated, or started to.

 

[Gun 4 Fun]

Originally posted by bmcgilvray:
I saw that second ring but attributed it to a scratch rather than a die problem. I've not seen a .44 Magnum case with a cannelure so don't think that's what it is.

Years ago, Federal used to put a slight knurl on their .44 mag cases.

I don't know if, or when they stopped the practice though.

 

[Skip Sackett]

To me it would seem we are missing some information. I for one would like to see the head of the case. Were these marks on the cases before you fired them Dave?

 

[David LaPell]

These cases were not fired by me, they were in a box of stuff that I picked up marked .44 rifle.

 

[Dan Cash]

Dave,
Hard to say with 100% certainty with out seeing dies, gun chamber and measuring things but it sure looks like too much pressure in a springy or ill fitting rifle action.