Strange Kaboom

[Hair Trigger]

Well, to answer some questions in the interest of somebody possibly learning something, I was shooting a starting load of Zip under a 180gr Missouri Bullet Co. SWC, CCI500 primer and once fired Starline brass. I have used this load before and was about 20 rounds into this batch when it happened.

I've never used Zip, and not familiar with load data for .357 using it, so I don't know how much a starting load is. It's a pretty fast powder, and if you've cut way back on how much you use in a load, you may have experienced a low density detonation. This can occur when the ratio of the volume of powder to the case volume is low, and occurs with fast burning powders. Additionally, since you're using a pretty heavy bullet for a .357, the pressure spike will be higher anyway, because of the inertia involved getting that big slug to start moving. There's an article came out several years ago that talks about low density detonations.

Light loads in large cases can explode (2007 update) - Reload Ammo | Founded By M.D. Smith in 1996

........reloading my 357 and 38 loads is my hobby, I am retired and I do not golf.

I like you already.

 

[crstrode]

50+ years ago while using a powder dispensor / aka measure , I missed getting a charge in a case ... ... That was so close it impressed the importance of getting powder into cases .

Similarly, I once traded a Ruger 22-250 varmint rifle complete with a batch of my reloads.

Just to be sure that I didn't make any reloading errors I weighed each and every one of the reloads before compleing the trade. Lo and behold I found a light one that turned out to be empty!

As far as I can tell that was the only reloading error that ever slipped by in over 40 years of lots and lots of reloading.

The new owner of the rifle reported back to me that not only was the rifle a gem, but all of my reloads were tack drivers

To this day I'm still very very happy that the mistake was discovered and didn't squib that gun. If I had not let that rifle go, I very well may have ruined it myself!

 

[SS336]

I am glad you are ok. That could of been a lot worse.
I have been reloading since 59-60 and have not had an accident. Reading this kind of thing reminds us that it can, indeed, happen to anyone.
Being kind of a Luddite I still use a beam scale to set my powder measure and a single stage press. It is slow sometimes, but maybe a good thing.
Again glad you and shocker are ok.

 

[GeoJelly]

sjs - Sorry about your incident and glad you walked away from it! I am also not familiar with Zip. But, as I go up in years (four behind you), I use bulkier powders, lately Blue Dot for 9mm & .40. Single charges almost fill the case in 9mm. The .357 (and .38) cases are so tall that they present a special problem for us folks with vision issues. I addressed that issue by switching to MBC cast bullets and Trail Boss for range use.

 

[STORMINORMAN]

Interesting that in one of the discussions an SEE (Secondary Explosion Effect) is specifically limited to low density loads of SLOW (vs. fast) BURNING POWDERS in large cases.

Multi-mllions of 2.7gr Bullseye & 148gr wadcutters would seem to bolster that opinion...?

Cheers!

P.S. They guy fire-forming 470 Ackley cases out of 45/70 brass with an undersized .458" bullet STILL has me scratching my head!

 

[glenwolde]

I wish I had a dollar for every post I've ever read that touted the superior safety profile of the single stage press. After reading many incidents of this type and the circumstances surrounding them I have come to the conclusion that it just isn't so. In fact, that very belief may be a contributing factor in and of itself.

Sometimes a post will say something like "it's just not possible because of my process". Well, that right there is the problem, their belief that their process is infallible when clearly nothing is infallible.

As for myself I find I pay much closer attention with a progressive because...well...you kind of have too. The problem I have with single stage presses is it's so boring. So boring I have a hard time maintaining focus on the 100th identical operation. The simple repetitiveness of it allows my mind to wander. I find myself double-checking what I just did all the time. Much more so than when I'm running the progressive.

So be honest with yourself. Do you ever find yourself wondering where you're at when loading? If that happens to you it's a warning flag.

It doesn't matter what you use. It's about your process but more importantly how well you are able to follow it and how well it suits you. This is what suits me, it might not be right for you. I spent decades operating far more complex equipment than reloading presses so perhaps it's just suited to me.

Yes, the bulky powder solution is a good one. Pretty hard to double charge a case when it won't fit. But you sure are limiting yourself. But if that's what you came up with because it's what suits you, I'm fine with that.

 

[Ruger 13]

What was the load?

 

[garbler]

Late on this thread but the OP said,

“ But it is also strange. I did not notice any increase in recoil when it went off.“

it’s not strange at all as the pressure was released out through the cylinder walls. Sorry if this was already noted

Addendum: a very common reaction with cylinder blown revolvers

Rick

 

[m75rlg]

Single stage press, weigh each charge on a beam scale, dump from scale pan into primed case, do not set case down, insert bullet into case, insert case into press and seat bullet. Examine completed round, and if it passes then it can be placed in tray. (No need for speed. This is a hobby, not a business.)

Have used this process for handgun and rifle for about 47 years, had one squib load in a .44 mag target load with simi wadcutter. That load had unburnt powder in case and barrell, and therefore must have either had a weak primer or somehow I contaminated the powder or primer. (Moisture or lub on fingers only possibility I could come up with to have a 1of 50 malfunction.)

That is the way a gunnersmate taught me while in service, and I have seen no reason to try to change or modernize the process.

Glad the OP was not injured.

 

[max]

Many years ago, American Handgunner had an article on SEE. I have never thought of 2400 as being a fast pistol powder.

 

[joe44va]

Welcome to the club.
Glad you're OK.
To me, one of the advantages of a revolver is that the bad stuff tends to go sideways when the SHTF.

 

[2152hq]

I still use scoop measures for most of my reloads.
Minimum loads right out of the loading manuals work fine. I've never had a paper target travel more than a couple feet after getting hit.
Actually even when used for hunting deer by a couple of other people they have done well too.

A single stage press.
I check the scoop measured charge on my old Redding beam balance scale that I've had since the early 60's.
I don't like electronic scales.

I charge one case,,then insert the bullet,,then seat that bullet.
One round loaded.

On to the next one.

I don't weigh each scoop charge. But I do weigh perhaps every 10th one to make sure I'm in sinc and getting a constant weight. They are very accurate. A powder measure is nothing more than a closed volume scoop measure after all.

I do reload 12ga on a MEC progressive. You do /should watch to make sure everything is working correctly and speed is not the primary goal.

The charge bar can jam on it's travel betw powder and shot drop. That can leave a shell w/no shot. Not a real big deal. More of a pain really when the bar releases and the shot drops unexpectedly and it's a pick up on aisle 6.

Powder bridging can be an issue and I've had that happen. You get a partial drop into one hull. Then the rest of that charge plus a normal drop all into the next hull.
You most times won't realize the extra when loading as the leverage on the machine will still crimp the hull OK. You will notice when you pull the trigger though.

When you do a continuous, repetitive exercise like reloading can be, there becomes more and more chances for a mix up in an assembly line mind numbing activity.
Slow it down a bit and take notice of things going on and it breaks the near trance producing monotony of what it can be.

 

[len917]

Single stage press, weigh each charge on a beam scale, dump from scale pan into primed case, do not set case down, insert bullet into case, insert case into press and seat bullet. Examine completed round, and if it passes then it can be placed in tray. (No need for speed. This is a hobby, not a business.)

Have used this process for handgun and rifle for about 47 years, had one squib load in a .44 mag target load with simi wadcutter. That load had unburnt powder in case and barrell, and therefore must have either had a weak primer or somehow I contaminated the powder or primer. (Moisture or lub on fingers only possibility I could come up with to have a 1of 50 malfunction.)

That is the way a gunnersmate taught me while in service, and I have seen no reason to try to change or modernize the process.

Glad the OP was not injured.

My process is pretty much the same as your. I don't have a single stage press but I use a Lee turret press as a single stage press meaning I prime, charge by hand, seat, crimp each case by itself. I don't use auto powder meters just a beam scale.,

 

[LoboGunLeather]

Focus of this discussion has been on reloaded ammunition and the reloading process, which is very probably the cause of this incident.

In the back of my mind there remains the picture of that tiny little sliver of steel that forms the cylinder walls of a J-frame .357 revolver. I'm sure that S&W is as careful as anyone in the business, but I'm also aware that they are producing very large numbers of these products, and the SLIGHT POSSIBILITY remains that a previously undiscovered flaw existed in the steel billet from which that cylinder was machined.

Such a flaw may, or may not, be detectable by S&W warranty service personnel, perhaps using high magnification to examine the structure of the metal at the point(s) of failure, or perhaps other technical means of analysis. Whether or not such an examination will be conducted, and whether or not S&W might choose to share the results, is an open question for which there may be no answer.

For some reason I continue to recall all the years that .38 Special was the most powerful cartridge for which J-frame revolvers were chambered, and S&W specifically recommended against +P (high pressure) loads in the J-frame revolvers. That company position was changed, modern J-frame revolvers in .38 Special were rated for +P ammo, and new models were offered in chamberings including .357 magnum.

Steel alloys (both carbon steel and stainless) have evolved over the years, and manufacturing techniques have been developed to a higher level of precision than seen in prior years. Have these been sufficient to justify the new magnum J-frames, or was the decision merely a marketing choice to capitalize on consumer demand, perhaps accepting the occasional failure as a cost of doing business?

Speculation, nothing more. Exercising my gray matter here, not pointing fingers or making accusations. Maybe worth thinking about, maybe not.

 

[BLUEDOT37]

In the back of my mind there remains the picture of that tiny little sliver of steel that forms the cylinder walls of a J-frame .357 revolver.

If you're referring to the traditionally thinner metal at the cylinder stop notch don't forget that S&W 5-shot J-frames have the cylinder stop notch at the thickest part of the cylinder, between the chambers.

While any flaw can happen, & can't be completely ruled out on a new purchase, factory proof loads should run between 47K & 50.5K psi per SAAMI standards.

As we know though, S&W normally only fires them in every other chamber in new revolvers.

.

 

[BLUEDOT37]

Single stage press, weigh each charge on a beam scale, dump from scale pan into primed case, do not set case down, insert bullet into case, insert case into press and seat bullet. Examine completed round, and if it passes then it can be placed in tray.

Some years ago (many actually now ), I changed over to doing it this way too.

I use a RCBS Charge Master 1500 to dispense/weigh the powder & routinely check it's charge weight on my beam scale along side of it.

The potential problem arises when the process gets interrupted in mid-stream, for one reason or another, & you start back dispensing powder again & miss the small powder charge in the large case that's already there.

It happens. You just have to always try to keep the mindset to double check before proceeding when you get interrupted.

Large charges of slower powders in voluminous cases is the easy answer but that's not always possible or practical.

Having been down that road, I know you just have to stay wary.

(I adopted making the first test powder charge, before I start actually dispensing for loads, a double-charge so I can be better alerted if I see that fill amount later.)

.

sjs, sorry it happened but I'm glad you're okay. Hopefully S&W can be of help.

.

 

[STORMINORMAN]

Actually, I research powders to determine where I can use a LEE powder scoop to get as close to a desired load as possible, put that into a balance beam scale as a 2nd check, then into a prepped case.

Sometimes it is 2 scoops... But, in this manner I'm checking the powder by both volume & by weight: a digital scale to cross-check the initial loads is a further way to insure I am loading what I intend to load.

A LEE #.5 scoop of Bullseye works wonders for quite a few different bullets and calibers: I can dump that into the pan of my Ohaus and from there into a prepped case pretty fast, even with a trickle or two... Whether it is one at a time, or 50 in a loading tray, seating the bullet and the subsequent crimp is no challenge. I'll confirm OAL and all go through a case gauge as a final check.

If it happens to be a new load I have even been known to do a plink (plunk?) test, sometimes with multiple barrels, to insure I have done everything I can.

Once I have a load confirmed it is quite easy to increase my productivity. I'm basically hand weighing each load, checking OAL and chambering for each round.

Never the less, I have still experienced 3 primer only "Poofs"...! Not enough powder to work the action on a Semi-Automatic pistol, nor move a bullet past a forcing cone on a Revolver, but enough to get my attention.

I'm only human... Born to make mistakes.

A double charge is the one I totally seek to avoid. A partial charge (which can be as bad, or worse, depending?) can occur, but there would usually be some obvious physical evidence. Anything tipped over, dropped, powder on the bench, etc., gets a full re-do.

Reloading is not rocket science: is it the perfect time to be OCD &/OR anal retentive?

Why not?

Confession is over: back to the bench!

Cheers!

 

[max]

I have often wondered if those primer"poofs" aren't bad primers.

king OAL and chambering for each round.

Never the less, I have still experienced 3 primer only "Poofs"...! Not enough powder to work the action on a Semi-Automatic pistol, nor move a bullet past a forcing cone on a Revolver, but enough to get my attention.

 

[STORMINORMAN]

I have often wondered if those primer"poofs" aren't bad primers.

Two were in 9mm, one a 38 Special. No indication of any powder, somehow...

Not really squibs, per se? Action in the pistol did not cycle: you could see the bullet in the forcing cone gap. Knocked them out with a dowel.

Hopefully I learned my lesson.

Cheers!

P.S. Confession is good for the soul...

 

[BB57]

I'm so glad that you're okay! In just over 41 years of reloading, I've never had this happen to me. But seeing pics of things that have happened to others, keeps me diligent and aware of what I'm doing.
I've loaded ammo starting with a Lee Classic Loading kit, RCBS Reloader Special single stage, Lee Turret Press with auto advance and Lee Pro 1000 progressive. No matter what equipment you use, safety is #1 priority.

Hope you get some good news from S&W and also hope you figure out what went wrong. Let us know on both counts.

Agreed. I’ve been reloading since I was 12, that’s 44 years and counting (still on all 10 fingers with both eyes).

I’ve been using a Dillion 550 for about the last 20 years and I think it’s just about the ideal progressive press, provided you put a light in 6e tool head so you can observe the powder level in the charged case.

It’s manually indexed so you remain in in complete control and if you experience anything strange you can stop, observe, and correct what ever is amiss on the shell plate very easily.

It also allows excellent feel in everything from primer seating to sizing, belling the case and seating the bullet. You don’t have to use it long to know it well and be able to see, hear and feel exactly what is going on.

But like any press, you have to pay attention and if you are ever in doubt stop, assess and if necessary pull down what ever you just loaded that might be suspect.


There are some things I do to stay organized and avoid confusion:

1. I put the basic load data on a card in the powder measure. You won’t mistake what’s in the measure.

2. The only powder allowed on the work surface is the powder being used on the press.

3. I place the sleeve from the primer package over the primer feed tubes and on the primer feed itself

4. I also try to keep the bench fairly clean and organized.