My first case head separation

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Mr_Flintstone

Mr_Flintstone

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Had my first case head separation today on some .357 magnum. Three cases separated the same way.
F3B10305-F4B0-4EF7-A45E-50CC2346B6E8.jpeg
The load was 8.0 gr Bullseye under a 125 gr XTP from a Henry rifle. Funny thing was that these cases all passed the paper clip test before the last loading. They’ve all had that funny ring around the bottom since I fired the factory Federal 158 gr sjhp. Been loaded about 10 times.
 
Mr_Flintstone said:
Had my first case head separation today on some .357 magnum. Three cases separated the same way.
View attachment 906283
The load was 8.0 gr Bullseye under a 125 gr XTP from a Henry rifle. Funny thing was that these cases all passed the paper clip test before the last loading.
Click to expand...

That is most strange. I honestly thought that case separations on straight walled cases were an oxymoron. With bottle necked cases, pressures hold the front of the case to the chamber, and while pressures build, the sidewalls have to stretch so the base can touch the bolt face. But, straight walled cases, they are straight!

I guess pressures were enough to fix the front of the case into place, and then the sidewalls had to stretch till the rim flattened out on the bolt face.

This is unusual and I wonder what the head space is in your rifle. That gap, "headspace" is a controlled distance. I don't know the number, but I would think it is around 0.006" or less. Your load is on the maximum end of old data on 125's with Bullseye. Alliant no longer publishes 357 Magnum data with Bullseye and the 125 grain load. Might be the pressure climbs too fast with component differences. I would recommend 2400 or W296/H110.

How rough are the cylinder walls on your rifle? A little oil, grease, sizing lube, or wax on the case would have prevented the case from sticking to the chamber.
 
This one is in the category of things I haven't seen and consider unlikely but always in the realm of possibility. Did you see any damage in the Chamber area from Gas cutting
 
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All the other brass I have is still in very good shape; and loaded many times. All of the Federal (from Walmart 158 gr factory SJHP) cases have had the ring around the bottom since the factory ammo was fired. Some were originally fired from the Henry, and some were fired from a S&W mdl 19. I rarely push any hand loads to published max, and never past published max.


Slamfire said:
That is most strange. I honestly thought that case separations on straight walled cases were an oxymoron. With bottle necked cases, pressures hold the front of the case to the chamber, and while pressures build, the sidewalls have to stretch so the base can touch the bolt face. But, straight walled cases, they are straight!

I guess pressures were enough to fix the front of the case into place, and then the sidewalls had to stretch till the rim flattened out on the bolt face.

This is unusual and I wonder what the head space is in your rifle. That gap, "headspace" is a controlled distance. I don't know the number, but I would think it is around 0.006" or less. Your load is on the maximum end of old data on 125's with Bullseye. Alliant no longer publishes 357 Magnum data with Bullseye and the 125 grain load. Might be the pressure climbs too fast with component differences. I would recommend 2400 or W296/H110.

How rough are the cylinder walls on your rifle? A little oil, grease, sizing lube, or wax on the case would have prevented the case from sticking to the chamber.
Click to expand...

They have never stuck in the chamber. They chamber and eject with little effort.

The load data was from the Alliant 2000 publication that called for a max of 8.4 gr, so it should have been a mid level load using a 10% reduction (7.6-8.4) for minimum.

I believe that there is something squirrelly going on with that brass, and I plan to chuck the rest of it. I think I’ll get some measurements from it first though.
 
I have never in my 48 years of reloading seen case head separation in a straight walled case. I have old Winchester cases that I have shot hard since the 1990s that I just now have to pitch due to loose primer pockets and have never had one separate like that.

Are you shooting .38 spls out of your rifle and not cleaning the chamber? Something has to be grabbing that brass hard and hanging on when it's fired to stretch it enough to pull it in half at the week spot. There are dark specs on the upper end of the case.

I agree with Slamfire, use a slower powder.
Wow!!
 
I measured the base of these brass at the web, and it measured about .3767-.3770”. I measured some 38 special and some Armscor .357 brass in the same place, and the measured about .3779-.3781”. I don’t know if that’s enough difference to cause this or not, but this brass is going bye-bye.
 
tightgroup tiger said:
I have never in my 48 years of reloading seen case head separation in a straight walled case. I have old Winchester cases that I have shot hard since the 1990s that I just now have to pitch due to loose primer pockets and have never had one separate like that.

Are you shooting .38 spls out of your rifle and not cleaning the chamber? Something has to be grabbing that brass hard and hanging on when it's fired to stretch it enough to pull it in half at the week spot. There are dark specs on the upper end of the case.

I agree with Slamfire, use a slower powder.
Wow!!
Click to expand...
I shot some .38 specials just before I shot these .357 mags. They were 125 gr loaded with 4.3 gr 231. I think that dark spot is just a shadow. I went back and looked at the brass, and it was pretty clean. You might be on to something with the .38 special though. I’ll give the gun a good scrub.
 
Wonder if that Henry’s lever action is up to spec. I’d be inclined to have it checked. That load is not quite max but the pressure is up there. Pushing 38,000 psi. Lyman Pistol and Revolver Handbook 3rd edition.
 
Because of the way lever action .357s lock up at the rear of the bolt, there is some flexing that goes on when the round is fired. This proceeds to stretch the cases. This is why the Speer manuals recommends only virgin or once fired brass when loading max loads for a .357 lever rifle. I would assume after ten loading the cases were getting stretched thin where it thins at the top of the case web. Not unusual for handgun caliber carbines.
 
whughett said:
Wonder if that Henry’s lever action is up to spec. I’d be inclined to have it checked. That load is not quite max but the pressure is up there. Pushing 38,000 psi. Lyman Pistol and Revolver Handbook 3rd edition.
Click to expand...
That’s a lot higher than what I have. Alliant from 2000 gives 8.4 gr @ 32,800 PSI. I figured 8.0 gr would be somewhere around 30,000 psi.
 
I used to get those a lot when I was full length carbide sizing my 45Colt brass for use in my huge chambered 1894.

Partial sizing just to where the base of the bullet sits will fix it or get tapered steel dies that don't work the brass nearly as much but require lubing.
 
Mr_Flintstone said:
That’s a lot higher than what I have. Alliant from 2000 gives 8.4 gr @ 32,800 PSI. I figured 8.0 gr would be somewhere around 30,000 psi.
Click to expand...
That’s ball park. Max listed in the book I quoted is 8.6. for a 125 JHP. At 38,400. 6/10 of a grain isn’t much you could easily inch up if using a powder measure. It’s one reason I tend to stay away from full loads in hand guns. Rifles different story perhaps. At any rate case head separation could be more than just a nuisance. I’d urge caution and dump that case lot. It’s another reason to maintain cases in “lots” and track times fired.
Excuse if preaching to the choir.
 
The low ridge is where the solid head transitions to the thin wall, not unusual at all. I don't size down that far.

High enough pressure can cause a separation in .38 Spl or .357 cases. A fellow THR member posted this years ago.

.38 Spl, grossly overloaded.
jfh's Seperated .38 Spl Brass - THR - THR Size.jpg
 
Walkalong said:
The low ridge is where the solid head transitions to the thin wall, not unusual at all. I don't size down that far.

High enough pressure can cause a separation in .38 Spl or .357 cases. A fellow THR member posted this years ago.

.38 Spl, grossly overloaded.
View attachment 906370
Click to expand...
That is a five round chamber, something you see in pocket pistols! The owner is lucky the cylinder stayed in one piece. I can understand case head separations in revolvers with high pressure loads, as the things are actually very flexible. So a real high pressure load will stretch the structure, and thus, the case will stretch beyond its breaking point. I guess the Henry is also pretty flexible. Still, very unusual.

I would again recommend against using Bullseye powder for magnum velocities. If Alliant does not list it anymore, it is because they can see variations in the pressure curve with modern piezo electric gauges, something they could not back in the copper crusher days. The copper crusher data just gave a maximum pressure. That was a valuable data point, but instrumentation and electronics have improved to the point the pressure rise can be plotted out real time. Bullseye is an outstanding, low charge weight, low pressure, low velocity powder. I never tried to use it at magnum velocities and I don't know many that do. The OP's rifle will shoot faster, and probably have less issues, with 2400 or W296/H110.
 
keep that brass, down the road you might want to compare it or investigate it further. always happens to me a few weeks after I discard something - wish I kept it so I could check it again or take a pic from a different angle or something.
 
It good the brass let you know where you were. Glad you are ok.

I played with Bullseye and 158s in .357mag. It was the only time I had sticky extraction with anything I've put in my Taurus 669. I've never tried it again. 8 grains is a good bit of Bullseye in a .357 case. More than I would be willing to put in there. Just my experience. YMMV
 
Bullseye seems to be the wrong powder for .357 magnum loads. Burns too fast. I have looked at all my modern reloading manuals and can't find a load for a 125gr. bullet using bullseye. Seems to me anyway that 8 grs. of bullseye and a 125gr XTP bullet would be a pretty stout load. IMO.
 
Jack B. said:
Bullseye seems to be the wrong powder for .357 magnum loads. Burns too fast. I have looked at all my modern reloading manuals and can't find a load for a 125gr. bullet using bullseye. Seems to me anyway that 8 grs. of bullseye and a 125gr XTP bullet would be a pretty stout load. IMO.
Click to expand...

^^^ I agree. Stout loads, multiple loadings in the same cases used in a lever action rifle......case head separation.

Again from the Speer #14 manual under .357 rifle.......

All lever-action .357 magnum rifles have bolts that lock at the rear. This allows the bolt to spring slightly during firing, stretching the case. Use only new or once fired brass for maximum loads.
Click to expand...
 
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