Any Idea What Caused This?

[trky chsr]

These were shot in a S&W M29. They are 44mag handloaded with 7gr of Unique under a 240gr lead bullet. I keep track of my cases and they have been loaded about 7 times (from new R-P brand). One of these was from my latest loading the other from a previous loading. TC

 

[Culina]

I think you found the limit for that brass or your M29 has extra wide chambers. This happens to me sometimes too but usually its in the middle of the case which is not as concerning to me as having happen towards the head.

 

[MichiganScott]

Dies are a little on the small size of specification and the chambers are on the large size. The brass is overworked.

On the other hand, I had a bunch of R-P cases that split halfway up the case on the first loading years ago. I lost about half of them. I talked with a Sierra reloading tech and was told that sometimes you simply end up with a bad batch of cases. The other half of the batch are still being used without further loss.

 

[Nevada Ed]

Seven times for a 44 MAGNUM is pretty good.............

Just cases getting wore out.......and as stated, some are not as high in quality for one reason or another.

Also notice that the pin holes are right at where your die stops, which is also the thickest part of the base, below the holes.
Your gun and loads are holding up well, just that the cases are wearing out............... it happens.

I would save a few of them for "Dummy Loads" or you can toss them.

 

[J. R. WEEMS]

I am reminded of some Federal 32 mag brass, and FACTORY loads that split-- the brass was just too thin, even from the factory. Chuck them and move on. 7 full loads of 44 mag is a lot, as had been said. I wouldn't have a complaint if it were me. For target stuff I wouldn't worry, for hunting, I never use new brass or brass fired over 6 times if ANY hint of a problem. Pays to stay on top of such things regardless. JMHO of course. :)

 

[Kilibreaux]

These were shot in a S&W M29. They are 44mag handloaded with 7gr of Unique under a 240gr lead bullet. I keep track of my cases and they have been loaded about 7 times (from new R-P brand). One of these was from my latest loading the other from a previous loading. TC

It's called "incipient case head separation" and has been known for eons.

Basically, when you fire any cartridge the case expands to fit the chamber. The base is so thick it tends to expand back to fully contact the breech face. The result is case stretch that shows up as a bright ring around the case just ahead of where the case web tapers into the case body. Eventually the case will separate at this point.

SEVEN loadings is a lot for full or near full-house .44 magnum.

Also consider partial resizing your PISTOL cases...just like bottlenecks they don't "need" to be full length sized. Adjust your die to size just the neck and maybe a bit more. Yes they will probably require a firm push into the chamber but the case head-to-case body separation will be delayed.

 

[Nemo288]

Consider moving to the Redding double ring carbide sizing die.
It sizes only the neck to grab the bullet.
The rest is not sized much at all.
It also has the advantage of positioning the cartridge in the
middle of the chamber, increasing accuracy.
This is neck sizing for revolver rounds.
No, they don't end up being cylindrical any more.
Yes, it works.

===
Nemo

 

[BLUEDOT37]

Split cases

I guess I've been lucky. In over 40yrs of reloading magnums I've never had a case split there. Usually the primer pockets get loose or the mouths get a split.

The cases don't look bulged & 7grs/Unique is a reduced load. Wonder if that was what the other (6) reloads used?

 

[Yorkie Man]

Out of all of the brands of pistol brass I have used the R-P is the one that I have had the most case splits with. 7 grains of Unique is not a hot load. I have some 20 year old that I recently scraped because of mouth splits that I have reloaded 25 times. All of the loads were mild with cast bullets. On the other hand I bought some R-P .45 Colt brass new that I only got about 3-4 reloads out of, all were discarded because of case splits.

Mike

 

[Forrest r]

Out of all of the brands of pistol brass I have used the R-P is the one that I have had the most case splits with. 7 grains of Unique is not a hot load. I have some 20 year old that I recently scraped because of mouth splits that I have reloaded 25 times. All of the loads were mild with cast bullets. On the other hand I bought some R-P .45 Colt brass new that I only got about 3-4 reloads out of, all were discarded because of case splits.

Mike

I'm not a huge fan of r-p brass either, most of the time it's too hard from the factory. Then it gets work hardened every time it gets used/shot/reloaded. Annealing the cases will stop this from happening. But I'd rather just buy a better quality brass.

I had an old 4" bbl's 29-2 that would do the same thing in the winter time in ne ohio. I think it was a combo of an oversized cylinder along with work hardened brass and cold temp that made the brass even more brittle.

forrest r

 

[Green Frog]

As I read this I keep wondering whether some folks read the OP. Seven (7) grains of Unique™ in a 44 Magnum case is a very mild load... bordering on 44 Special power and pressure. I'm going to go with tolerance stacking due to a tight die and a loose chamber, and perhaps thin or brittle brass. As such, if this continues I'd investigate having my sizing die polished open a thousandth or two, and maybe look into other lots or even brands of brass. JMHO, YMMV.

Froggie

PS For the record, what brand of loading dies were you using, and were they steel or carbide? I'm guessing carbide from Lyman as I've found their dies to run to the tight end of the standard specs.

 

[papajohn428]

It's called "incipient case head separation" and has been known for eons.

Basically, when you fire any cartridge the case expands to fit the chamber. The base is so thick it tends to expand back to fully contact the breech face. The result is case stretch that shows up as a bright ring around the case just ahead of where the case web tapers into the case body. Eventually the case will separate at this point.

It is most assuredly NOT "incipient case head separation". What you are "describing" (a borrowed quote, most likely) is not what the OP shows. Bright ring? Where? This is classic stress fatigue, plain and simple. Case head separations are horizontal failures, not vertical.

 

[2152hq]

As I read this I keep wondering whether some folks read the OP. Seven (7) grains of Unique™ in a 44 Magnum case is a very mild load... bordering on 44 Special power and pressure. I'm going to go with tolerance stacking due to a tight die and a loose chamber, and perhaps thin or brittle brass. As such, if this continues I'd investigate having my sizing die polished open a thousandth or two, and maybe look into other lots or even brands of brass. JMHO, YMMV.

.....

I'd agree with this. Others have stated the same.
If you can,,try another sizer die on a handful of the same brass w/the same load. See how long they last you. Maybe a friend has a 44mag sizer you can borrow for the experiment.

Or try partial sizing of the brass as suggested. Just enough to grip the bullet. Shouldn't need FL sizing with that load I wouldn't think. Again do a test of a another handfull of the same brass and load with partial sizing and see if the same problem shows up,,or not.


The "incipient case head separation" issue is generally one of excess headspace in conjunction with overworked brass. Mostly seen w/ a rimless or belted cartridge but it can happen with any of them.
The separation from the continuingly thinned/stretched out brass wall occurs in a line running around the case just ahead of the thick head portion instead of verticle crack(s).

That stretched out thin ring of brass case wall running around the case down by the head is what you can feel with a piece of wire bent to a tiny point and dragged along the inner side wall surface.
When they get so thin they let go and you actually do get the case head separating from the rest of the hull at that point. Not a good thing.

Worth a look and some probing inside the cases just to make sure. At least you can verify or elliminate that as an issue too.

Just my thoughts

 

[Culina]

I ended up with 6 extra .44mag cases from a bulk brass purchase. They are nickel plated Star Line head stamp. I didn't know what else do to with them so I decided to load them hot until they fail just to get a baseline. At any rate, I have fired them eight times so far with a 200gr FMJ and 27gr of W296.

They still look fine but I need to get some more 200gr bullets.

I have also had new factory .44mag loads split on the first firing but several reloads later, the rest are still doing OK.

 

[buck460XVR]

7 gr of Unique under a 240 lead bullet is a powder puff load in .44mag. One should be able to load those cases until the necks split. IMHO, that is not case head separation, that is either stress caused from over sized chambers, a bad batch of brass or brass that has been contaminated from something and weakened or a combination of those.

 

[rck281]

Just something to check -- if you are using a carbide sizing die, you need to leave a little space between the bottom of the die and the to of the shell holder -- maybe the space of the thickness of a nickel. It may be that the die is too far into the head and causing a problem. Hard to tell without seeing your setup and measuring the case.

 

[Engineer1911]

Brass fatigues and cracks, when you never know. I shot a S&W M52 for about 8 years. R-P brass failed at the second firing, Federal and Winchester might make 4 reloads. Military 38 Special brass never failed. My load was 3.0 grains of Win 452 or Bullseye powder with a Lyman 150 gr wadcutter. Factory wadcutters ejected ~8' and my reloads ejected ~4' from the gun, so I was shooting a mild load.

You have a fatigue crack from work hardened brass -- a vertical split anywhere on the case -- usually at the mouth . Case separation from stretching is a circular crack around the case.

 

[trky chsr]

Thanks for all the replies. Lots of good info. For your info I use Lee carbide dies. I also reload 38/357, 45 LC and 9mm. I have RCBS dies for the Colt, Lee for the others. I was just curious as I have seen a lot of splits at the case mouth but never at the base. I will try raising the sizing die a tad and see if this shows up again. TC

 

[thomasinaz]

Were these cases fired in the same chamber? The split is in the same place on both cases, which appears to be where the bolt notch is in the chamber. Maybe an overpressure round was fired previously in one chamber, causing a slight bulge, allowing this split. Probably a remote possibility, but worth checking to be safe. 7 gr Unique with a 240 is a light load. The cases shouldn't be splitting at these pressures.

 

[fredj338]

I've loaded a lot of 44mag, some of it to nuclear levels, never seen a case failure. Sure, they work harden & crack at the mouth,m but never seen a case head failure. I suspect a bad lot of brass, particularly that vertical failure. If they were separating, like a rimmed case will, it would be horiz. Toss the brass, imo all of it if from the same lot.

 

[Treeman]

Brass musta been Obamanated....
Seriously, Good brass alloys properly annealed keep going and going BUT tweak the alloy or don't get the annealing right and case life plummets. I have a large lot of military ammo that splits almost every case upon firing. It was loaded at the arsenal about 35 years ago and age hardened to this state. Some old .22 rimfire ammo has been known to do the same. On the other hand I have some 70 year old 30-06 cases that have never given a problem in multiple reloadings. Likewise some .45 acp and .38 special cases from the 1960s.

 

[GBertolet]

One thing to consider if your problem turns out to be an oversize chamber or undersized die. Try adjusting your carbide sizer, to size 1/2 of the case. You will not work the back half of the case, and at 7 gr Unique, you should get several firings before you have to full length resize. I had an issue of mid case splitting in a 45 colt , and this solved it.

 

[dla]

Not unusual for RP brass

Although I normally see it in the middle, not towards the case head. I've never seen this with Starline in 44mag, only Remington.

Here's my example:

 

[AveragEd]

I use Starline brass for my .38 Super and .45ACP loading and Remington for .38 Special, .357 Magnum and .44 Magnum as well as 90% of my rifle loads. I only load target ammo for the handguns and right now, my current batch of R-P .44 Magnum brass is on its 8th loading of a 240-grain Missouri LSWC over 5.5 grains of Clays. In 40+ years of handloading, I've never had a straight-walled handgun case split anywhere but the case mouth from being expanded and crimped repeatedly and that's after a lot more loadings than what I'm reading about here.

Now rifle brass is a different story and I only neck-size those cases but I watch the few belted magnum cases I still load for the "bright ring of death" just above the belt. You can also check cases for stretching with a large paper clip modified to "feel" for the impending separation along the inside of the cases. I've gradually replaced all of my belted magnum cartridges but two - the .257WBY and 7mmSTW (and the latter has been relegated to "collector" status) - with non-belted Remington Ultra Mags and Short Action Ultra Mags and the brass life is a lot better.

Ed