What happened? .357 Rupture

[Bruce51]

BTW, they were loaded with 7.1 gr of a flat circle powder.

That does sound like a medium range load like Unique, possibly not a factory load.
None of this is good news. It is amazing that such a small charge of powder flame cut the cylinder. Was there sealant around the bullet or just the primer?

The flame cutting of your cylinder, while annoying, is cosmetic and should not affect your gun, unless it causes sticky extraction.

Your gun, your call. I would just shoot the gun, lesson learned.

Bruce

 

[john traveler]

I'm not a degreed metallugist, but my engineering and technical subjects expertise has required me to study it.

Brass is work hardened by the repeated draw operations needed to form cartridge cases. Generally, annealing is performed after each cupping ("die stamping") and draw (deep cup extrusion) operation. The anneal "relaxes" the crystal structure and allows further draws up to near the elastic limit without cracking the brass.

True, brass (and other non-ferrous) alloys age because the copper and zinc crystals are held in a mechanical mixture or lattice work. It takes GENERATIONS for brass to age and weaken. What happens is atmospheric corrosion or contact with corrosive materials attacks the alloy, and induces microcracks in the crystal.

Ammonia for example, attacks the copper more than the zinc, leaving copper-starved regions in the surface of the alloy. This is more likely than hydrogen embrittlement, which DOES affect the brass if it is plated. During nickel plating, hydrogen molecules are trapped in the brass-to-plating interface and leaves weakened areas. This is the basis for the belief that plated cases are not as sturdy (cracks easier) as unplated cases. There are processes to relieve hydrogen embrittlement in plated objects (prolonged oven heating), and if done properly, there is no difference in case life between plated and unplated brass.

Cartridge brass made up to the early 1930s was harder and springier than those made after this period. You will frequently see cracked case necks in military rifle cartridges made in the first third of the 20th century. After this period, case neck annealing was standardized in US and european MIL-SPEC production of military small arms ammunition. The case colors seen on the neck and shoulders of military ammunition are intentionally left there as proof that the case neck anneal was done. In commercial ammunition, the case colors are polished off prior to loading and packaging. Cosmetics are important you know.

The final case mouth/shoulder anneal is done by passing a gas flame across the case. The body, web, and head of cases is intentionally left "springier" and left unheattreated after the last draw. Case heads need to be tougher than the case mouth.

Pistol and revolver cases are done differently from longer rifle cases. I believe their heat treatment is done in ovens and is a compromise between fully-hardened case heads and soft case mouths like in rifle cases. This places a premium on correct oven temperatures and times.

All of these operations are done on automated machinery, and it requires close human supervision to make sure the processes are correct.

You can probably see where the weak point is when bad brass is suspected.

 

[Bruce51]

John,Thanks for your explanation. I think your post should be a sticky as questions about brass are important to all reloaders.
Now I know why the nickel case always split at the mouth.
I also have some .38 cases that are really old which just keep going and going.

Good information worth having available for all future reloaders.

Bruce

 

[OKFC05]

I worked on the cylinder tonight. It is pitted, like a gas cut (which is what it is). I tried everything in my arsenal, including bronze wool, 0000 steel wool, Flitz, jeweler's rouge and a dremel polishing tip, etc. They shine, but, the pits are still there.

I believe these "blew" due to a variety of factors, the most being that the crimp is way too tight....
I'm still irritated!

There isn't enough crimp in the world to have made those cases blow. You just bought junk ammo and it damaged your gun. Lesson learned.

To repeat what several other experienced people have said, if you keep messing with the cylinder trying to make it "perfect again," you're likely to wind up with egg-shaped chambers and sticky extraction.

Then you'll really be irritated!

 

[Missionary]

Good morning
I would be contacting the seller also.. he should know what he is selling can be a potential disaster.

 

[rodell]

BTW, they were loaded with 7.1 gr of a flat circle powder.

That does sound like a medium range load like Unique, possibly not a factory load.

I thought the same thing when I saw the powder, but, it was much more potent than that. I didn't chrono them, but, they felt pretty "full".

I had to whack my impact puller on concrete for ten minutes on the first one I tried - that was the one where the core separated from the bullet. I've never had that happen before. The other half dozen I tried were pretty difficult to get out, too, but the core didn't separate. I've never had anything else come apart so hard. I'm going to put the crimp under the scope at work and see if there's anything there of note. At this point, this is just for my forensic interest.

Egg shaped cylinders would be bad! I certainly haven't caused that - yet. I realize the pits are cosmetic, although difficult to clean. They just bug me as I'm pretty particular, and, this "was" a mint piece. I'll see how I feel about it in a month!

Bob

 

[BUFF]

That Remington bullet design is designed to open easily. The jacket isn't particularly thick and there isn't a lot of it compared to other designs. They don't call it the "short jacket hollowpoint" for nothing! The jacket frequently separates from the lead core on impact with the target when fired. The jacket and core aren't bonded together, the jacket just wraps around the core. I had some of the old design Speer 3/4 jacket .44 bullets come apart when using an impact puller. It can happen with some bullet designs, the more fragile the bullet, the more likely.

The crimp doesn't look excessive to me.

I have had Remington handgun brass split in a similar manner on first firing, in .357 Mag, .41 Mag (old midrange lead bullet load!), .44 Special and .22 Rem Jet, usually factory-loaded ammo, not component brass, but never so far down towards the rim and through the web.

I am guessing it was loaded by other than Remington, judging by it's appearence. I have bought bulk new, unfired, primed brass made by both W-W and Federal that has red primer sealer, like that, but my experience with Remington brass has consistently been so bad (I started handloading about 1975) that I don't buy it unless it was the only choice at the time, like .22 Jet and .45 Auto Rim used to be.

That sure looks like a defective, brittle, bad bunch of brass, not R-P factory-loaded into cartridges, to me. I think the chance of defective heat treatment during manufacture is the most likely explanation. Be glad you don't have a lot more of it!

 

[moxie]

Looks like brand new Remington brass.

Bullets are Remington 125 gr. SJHP, semi-jacketed hollow point.

You can crimp the heck out of that bullet and after a point there is no more grip on the bullet, just deformation. The crimp looks good to me and shows no signs of over-crimping.

I'd return a few rounds to Remington with any box pieces you might have and ask for an evaluation. If they agree it's their product, they will likely replace it with new production. The 125 SJHP is still being produced. It's a great SD round.
If it's not their product it was made by some reloader using new components, but the quality of that finished round looks really good.
Either way it's their brass and they are going to be interested in this. I suspect there is a weakness in the brass due to poor annealing or embrittlement as discussed above. Remington is in the best position to figure it out and if you discuss it with them they will respond appropriately.
The chamber marks are just more of life's speed bumps.

 

[Bruce51]

puller

To salvage the bullets, try pushing them into the case first on a press.
That should break the seal and then you can put them into your
bullet puller. They should come out with a lot less force. If you do salvage the bullets I would suggest tumbling as well. The fact that the bullets are so tight would raise the pressure.

As OKFC05 said It's not the crimp. Almost sounds like the bullets were glued in place. Anything is possible with someone else's reloads.

Bruce

 

[El_Jefe]

Hhhmm....I just bought some p & r.

 

[rodell]

I just disassembled all of these loads, and, the brass was definitely "new". I decapped them so I wouldn't be throwing away "loadable" brass, and, the primer pockets were sparkly clean and only one primer seating mark.

As I pulled them apart, I swear some were glued in. Lots more effort on the collet puller vs. the "average" one.

Oh, well, on to another adventure.

 

[SW357Addict]

Never, never, never, never, never, never, never, etc. buy reloads at a gun show. That is your problem.

 

[rodell]

Never, never, never, never, never, never, never, etc. buy reloads at a gun show. That is your problem.

Well, at the time they were "bulk new", or so they were represented. Now that I reload extensively, I would never buy anything without a pedigree!

 

[moxie]

So, why didn't you send some back to Remington to see whether there might be a safety issue with the brass?

 

[rodell]

So, why didn't you send some back to Remington to see whether there might be a safety issue with the brass?

Mostly due to age. I couldn't place them exactly in time, so, it seems like it would tough for them to do anything about it.

I took the cylinder to Bolsa Gunsmithing in Westminster, CA while on a business trip. They polished it up; it looks like new. End of this adventure!