I don't believe this would really blow up...

[AJMD429]

Now I know it isn't a good idea, but do you think there is really any ordinary load data for 38 Special that if loaded in the longer 357 Magnum case and shot in a 357 Magnum gun, would be dangerously overpressure? Someone on another forum (actually two people) is insisting that would be very dangerous. The only danger I would expect is if the load was marginal or underpowered, maybe the extra space would create a too-slow bullet velocity and result in a plugged bore.

[Blaine]

Maybe (but, doubtful) a really light load of H110, 296, or, Blue Dot could cause a problem but I doubt it.....(always better to follow published loads....)

[olyinaz]

This is where a program like QuickLoad would really come in useful...

[Blaine]

Any powder that fails to fill the case properly runs the risk of positional-powder-high-pressure.......Remote possibility that that is.....

[El Chivo]

Any powder that fails to fill the case properly runs the risk of positional-powder-high-pressure.......Remote possibility that that is.....

I have read and heard that that's BS. Tell me how 2.5 grains of Bullseye fills the case?

The Lee Manual will tell you that loads leaving more space in the case are safe. I don't see how any could be higher pressure. The powders you are dealing with are fast, you have to expect all the powder to ignite. If you use less, what can it do, ignite twice?

These cases of "detonation" always come down to a double charge, from what I've read and heard. Personally I don't believe it, and I load down most of the time.

Reloading manuals usually start with a hot load and go hotter. Rarely do they expect anyone to want a light load. Since I do, this is a bone I pick with them. Let's see the full range of loads. Sure, we don't want a stuck bullet, but why start out with zip-a-dee-doo-dah? You might want a light bullet with low velocity for a backyard varmint. The loading manual starts at 1850 fps??? Come on.

[cas]

Yup... They say there's no such thing as detonation because they've never been able to replicate it in the lab.

I've never been able to get struck by lightning, so that must not exist either.

[Hobie]

I would want to know the specifics of the load, i.e. primer, powder, charge and bullet. Some people seem to think things are identical when they are not. They never did well at the kindergarten game of how is one thing not like the other.

[J Miller]

Now I know it isn't a good idea, but do you think there is really any ordinary load data for 38 Special that if loaded in the longer 357 Magnum case and shot in a 357 Magnum gun, would be dangerously overpressure? Someone on another forum (actually two people) is insisting that would be very dangerous. The only danger I would expect is if the load was marginal or underpowered, maybe the extra space would create a too-slow bullet velocity and result in a plugged bore.

Using the criteria stated above my answer is; No.

The .357 mag case is only .010" ( 1/10") longer than the 38. That is not much. The case walls are thicker as well. If the loads are safe in the 38 spcl case they will be safe in the .357 case with less pressure as well.

Detonation in handgun cartridges is a scam presented by squib load shooters who double charge their cases or seat two bullets as they crank off 10 million rounds an hour on their progressive loaders.

Joe

[Modoc ED]

Mike Venturino (sp?) has had two handguns blow up on him - both losing the top-strap and one blowing up a cylinder too. Both he said, had too much space in the case (under loaded) thus letting the powder lay down and explode when the primer was activated - detonation.

I'm not really up on the details. You guys could "Google" his articles and also look at the index of "Rifle" magazine and "Handloader" magazine. It's been awhile since I read those articles.

[mikld]

I'm with JMiller on this one. I started loading .38 Specials in '69 and .357 Magnums in '71 (yeah, so what!). You can safely use any .38 Special load data in a .357 Magnum case safely, I've done it. Every thing from 2.7 Bullseye w/wadcutters to +P loads all the way to magnum loads in magnum brass. The only difference is lower pressure/velocity than listed in the manuals 'cause of the larger case volume. As Blain says, stay away from H110/W296 and you'll be fine.

[Thunder50]

Detonation in a pistol cartridge is very real. Lost a 29 smith silhouette, that way. Not enough of a too slow powder. Each case was weighed to powder charge , inspected in the loading block,and a 295gr cast bullet seated (couldn't seat two if you tried).

noticed bullet strike after every shot. Came apart on the 6th.

It does happen

[AJMD429]

I haven't calculated the percent increase in 'empty space' for a particular load, but since many 38 Special loads don't even fill half the case, it seems like going up in size to a 357 Magnum case might shift the load from filling 35% of the case to 30% of the case, or something on that order. If the load I'm using is that CLOSE to the danger-level, I wouldn't want to be using it...!

Then again, H-110 supposedly will result in a squib that could lodge in the barrel if the load is reduced "more than three percent". . . I wonder how many people's reloading technique is so accurate that 10.0 grains is never accidentally thrown instead of 10.3 - I know we all pride ourselves on being meticulous, but a margin that close is kind of creepy. (Here's a good opportunity for someone older [a few on here] and wiser [many here] than me to chime in and say "reloading is not for the timid or careless"...yeah, I know that, but I like to have big margins of safety whenever possible.) Some powders seem definitely more 'forgiving' than most - to me the IDEAL powder would be just bulky enough that a lightly compressed load would not go over-pressure, and you could increment all the way down to loads that would repeatedly just exit the barrel and fall on your toes.

I think part of the problem (and danger) of reloading is the "lore" that is out there of "facts" that nobody has ever really investigated. Rumors turn into rules, then the real rules/laws of physics tend to be shrugged off along with some of the dumber rumors - yet the two are quite separate. Separating fact from fiction in reloading is important and is an ongoing thing for all of us, I guess.

Personally, I just have never used ANY reloading formula for powder charge that isn't specifically within the parameters of a MANUFACTURERS suggested data as to maximum/minimum. I will substitute a few things:

• I don't mind using a lead bullet in a 'jacketed' formula (as far as safety - not performance)
  I will use a different brand of case if it holds essentially the same volume of water
  I will use a different brand of jacketed bullet if it mikes the same diameter and the load is mild
  I will use a different brand of primer of the same type

I have never used load data for one cartridge in a 'similar' one, though I can see the rationale IF the cases were the same volume and similar shape, and the guns similar and strong. Never needed to do that though, since there is so much load data for the common cartridges out there. (You guys who shoot the odd-ball or wildcat stuff must have to do some guessing...)

I am suspicious of relying on "pressure signs", though I've seen a few in primers over the years (and one friend loaded what he said was a 30-06 powder charge for the 30 cal half-jacket 115 or so grain 'plinker' bullet, only in a 30 Carbine case, and kinda enlarged the diameter of the primer pocket - testimony to the Ruger Blackhawk he fired all six without problems). I just don't think I'd want to depend on "pressure signs" to show up then back off the charge.

I DO rely somewhat on chronograph readings, and figure if I'm using a proven powder for that cartridge, and getting normal-for-cartridge velocities, things are probably ok, but even there I could see why things could go way wrong.

Even more amazing to me though is that evidently you CAN rely on a little glued-on pressure transducer on the OUTSIDE of a gun's barrel to tell if things are safe. Unless I'm missing something, that means the outside of that gun is STRETCHING (and I know metal does that, but) is stretching so much that some little glued-on gizmo can RELIABLY stretch along with it and the degree of stretch (it surely is in millionths of an inch - or if much more than that it is too scary to think about), and then accurately translate THAT to within a few thousand PSI accuracy. Seems like witchcraft...

Anyway, still interested in others' thoughts.

[Old Savage]

From what seems to be commonly known, less than 90% charges of 110/296 can be dangerous and two stage ignition ( first kicking the bullet into the barrel and then the main charge going off) are dangerous. An Aside - why would we believe Venturino knew what went wrong and why - other than the gun blew up of course.

[44-40 Willy]

My plinking loads in a 357 Mag rifle are from 38 Special data. They work just fine.

[AJMD429]

An Aside - why would we believe Venturino knew what went wrong and why - other than the gun blew up of course.

'Cuz he's got a cool name, and writes articles, that's why...

Seriously, I agree.

It seems that the 'safest' powder could be the medieval black powder - sounds like if you push the ball all the way down onto the powder charge, any charge is safe towards the LOW end that will get the bullet out of the muzzle, and with 'modern steel' there are blackpowder guns right up there with the 375 H&H...

• http://www.ultimatefirearms.com/pdfs/ar ... ooting.pdf
  http://www.badbullmuzzleloaders.com/
  http://greenevilleoutfittersblog.com/20 ... zleloader/

[Sixgun]

How can "2 grains" of powder result in the destructive power of "15 grains"? There is a law of physics here.

All of this talk on detonation has mostly come when progressive loading machines became popular, coinciding with cowboy action shooting and also coinciding with marginal reloaders using these machines to load ammo to cowboy shoot.

I read Mike V's articles. I bet if you asked him now, he would give a different answer.

Yea, it was talked about many years ago when using below starting charges of slow burning powders but it was talk, I never did actually read of a proven incident regarding this practice.-------------------6

[J Miller]

To debunk the detonation in hand gun ammo by small charges of power just put 5.0 grs of 231 in a 45 Colt case. I suspect there is probably less than a 10% by volume fill of the case. Stick a 250gr bullet on it and you'll have a detonation .... NOT IN THE LEAST.
That load is right out of the Winchester loading data booklet for .45 Colt cowboy loads.

Mike Venturino needs to stick with black powder. He gets himself in too much trouble when he strays to ultra light smokeless loads.

You cannot get more pressure with less powder .... unless you double or triple charge it and / or seat two bullets. Progressive loading machines are not for rookies, or those who don't have the common sense to pay attention. There have been threads here, and on other forums about bad ammo that was sectioned and found to have two bullets in it. Or ammo that was pulled down and found to have two or three charges in it after a series of rounds with no powder.


If a measured, verified and visually checked load blew a 44 Mag in 6 shots it was either too high a charge for the powder and or bullet used, or the wrong powder, not a detonation.

The OP did not state the use of H110/296 in 38 special cases vs 357 mag cases. He stated: "any ordinary load data for 38 Special that if loaded in the longer 357 Magnum case and shot in a 357 Magnum gun, would be dangerously overpressure?" A case full of H110 in a 38 spcl cartridge is not an ordinary load anyway. There is way too much pressure for the cartridge and 99% of the guns that shoot it.

Joe

[Griff]

How can "2 grains" of powder result in the destructive power of "15 grains"? There is a law of physics here.
All of this talk on detonation has mostly come when progressive loading machines became popular, coinciding with cowboy action shooting and also coinciding with marginal reloaders using these machines to load ammo to cowboy shoot.
I read Mike V's articles. I bet if you asked him now, he would give a different answer.
Yea, it was talked about many years ago when using below starting charges of slow burning powders but it was talk, I never did actually read of a proven incident regarding this practice.-------------------6

I disagree about it comin' about because of cowboy action shooters. Sure, there've been squibs and the next cartridge blows the gun up. And, yes, a sloppy routiine or poor choice powder on a progressive can certianly lead to squibs. And I had a few when I was first loading on a progressive... mainly from trying to run as fast as I could, like probably 99% of new progressive owners.

But I first read of "detonation" back in the early '70s and IHMS shooters experimenting with slow rifle powders in handgun cartridges with heavy-for-bore bullets. And it's been an controversial subject ever since.

[Blaine]

Well.....Solid fule rocket motors have a hole up the middle of the charge so that more of the fuel is ignited causing higher pressure and thrust....If the powder in the case is lying horizontally, and it ignites across the top of the powder....That's the theory... the lab boys have not blown up a gun, but, they dang sure have shown impressively high pressure spikes that have been contained by the weapon....

[AJMD429]

If the powder in the case is lying horizontally, and it ignites across the top of the powder....

That's another interesting twist on things; if that is true (and I believe it is a factor), then worrying about that extra 0.1 grain of powder or extra 0.5 cc's of space may be LESS important than what position you were holding the gun in just prior to firing it...

I don't remember the source, but I do remember seeing an article about variations in velocity vs. whether the gun was tipped 'muzzle-up' or 'muzzle-down' just prior to firing, and some of the variations went WAY high or low, depending on the powder and cartridge (45 Colt and 30-06 were both in the data, if I recall correctly).

If reloading is like most other areas of human endeavor, we'll periodically realize that some of the things we've worried about are silly, and other things we weren't worrying about should have scared the dickens out of us. (It certainly happens in medicine...)

[kevind6]

My own suspicion is that most of these reports of light loads blowing up a gun were in fact double charges. This seems the more likely scenario to me....nobody wants to believe they screwed up in their reloading process so they exonerate themselves by blaming an under charge instead.

[1894c]

I would want to know the specifics of the load, i.e. primer, powder, charge and bullet. Some people seem to think things are identical when they are not. They never did well at the kindergarten game of how is one thing not like the other.

HOBIE...you're wisdom is incredible, made me laugh, expect it's so true... :)

[El Chivo]

if you want to talk detonation, how about the guy who didn't know how to read his scale, and loaded 38 special cases with 30 grains of Bullseye (compressed) instead of 3.0 grains?


---------------------------------------------------------------------

I'm reading up on this on the Internet, and some are claiming it happens with FAST powders and some with SLOW powders. So which is it?

There is some agreement on the following: Very low density loads (meaning the ratio of powder volume to cartridge case volume) of very fast powders under varying environmental conditions can create up to 4X normal chamber pressures and may cause the light load rupture to occur. Ruptured barrels can be symptomatic of too much powder (double charge loads, etc.). Ruptured cylinders and dissappearing backstraps can be sypmptomatic of a light-load rupture.

----------------------------------

Contrary to the ubiquitous old wives tale, detonation is NOT a consideration with fast powders such as Bullseye, no matter how light the charge is or how spacious the case.

The phenomena of Secondary Explosion Effect (SEE) is known to occur only with the slow powders at very low loading densities. Precious little is known about the mechanics of the phenomenon and it is not even known if the expression, Secondary Explosion Effect, is accurate. SEE, despite best efforts of the leading powder companies, cannot be reproduced in the lab,






----------------------------------------------------------------------

I think OS has it nailed - a partial burn, popping the bullet into the bore, where it gets stuck. Then the rest of the charge goes off. Still, would this violently blow up a gun if there's not a full charge of powder?

------------------------------------------------------------------------

Another theory is a comparison with granary explosions, where fine powder in the air ignites. Still, what is suspended in the air inside the case?

------------------------------------------------------------


Smokeless powder simply cannot detonate in the small quantities used in small arms ammunition. There is not enough mass for a detonation shockwave to progress through the charge.

Reports of reduced load blow-up's are generally in large magnum cases that are very over-bore. (Small caliber belted magnums)
It is thought by many, myself included, to be more closely associated with a bore obstruction.

1.The reduced load of slow burning powder is laying on the bottom of the case.
2.The primer flashes over it and doesn't get a complete high-pressure burn going.
3.The bullet moves from the case, and sticks in the first inch or so of rifling.
4.Then the rest of the charge lights off and pressure rises so fast the stuck bullet can't get out of the way fast enough.



IMO: "Detonation" blow-ups in handgun light loads are nothing more then double charges, or more, from faulty reloading procedures. It seems to be a phenonum that happens to pip-squeek load Cowboy action shooters more so then any others.

(Years ago, I saw it in light-load Bullseye shooting where star progressive reloaders were involved.)

Powder only has so much energy in it, and as I already said, cannot support a detonation in less then rail-car quantities.


-----------------------------


It has been theorized that during the initial phase of firing slow burning powder in large capacty cases can create a transition conditon during the time which the powder is inignited and starts to burn it does so with the powder granules in gas suspension so that they are burning individually and separately. This would create instantationus conflagration and could spike pressures to the point of blowing up the gun. It has never been duplicated in the ballistic laboratory. It has been show as being statistically possible by mathmaticians and there have been some unexplained rifle wreakings under these conditions but never in a lab. So it remains conjectual.



(the above is an explanation of a granary explosion, where flour suspended in the air can ignite)

[Thunder50]

J miller

Brand new can of powder

Charge was way too low ,I found out later

Hardly any recoil when it blew, thing I noticed was the flash. More recoil on the first 5.

So not too much powder, too little. I weighed every charge and visually inspected powder level in each case.

May not convince you it can happen, but you will not ever convince me that it cannot. I still have the remains of the gun and remember that day well. I shot IHMSA quite a bit then and was quite meticulous in the assembly of the loads I was going to test for my "new" gun.

[JohndeFresno]

J miller

Brand new can of powder

Charge was way too low ,I found out later

Hardly any recoil when it blew, thing I noticed was the flash. More recoil on the first 5.

So not too much powder, too little. I weighed every charge and visually inspected powder level in each case.

May not convince you it can happen, but you will not ever convince me that it cannot. I still have the remains of the gun and remember that day well. I shot IHMSA quite a bit then and was quite meticulous in the assembly of the loads I was going to test for my "new" gun.

Thunder50,

If you still have the data, I'd love to see what QuickLoad sez. It is supposed to warn you of high pressure, and I suspect that would be regardless of whether it is an overload or under load.

As for light .38 loads, I rarely use .38 brass for a these of reasons:
1) I have way more .357 brass
2) Less inventory problems
3) Don't fire my snub nose .38 that much
4) I subscribe to the belief that firing .38's in a .357 causes unnecessary buildup

On the other hand, you see warnings in most reliable reloading sources about using less than a certain amount - minimum loading; especially with slow handgun powders like N-110, H-110, Win 296.

Why not use something more suitable for the slower .38 loads, anyway?

Example: One of my .357 loads uses a 158 gr. SWC and 4.0 grains Unique for approx. 800 fps MV.

Alternately, for pure intellectual curiosity, you could rig a string to your .357, put it in a vice, get behind a barrier and try some light loads of slow powder...

[mikld]

AJMD429, I would say perhaps you're overthinking this. I've not heard of "case capacity danger level" (2.7 gr. of Bullseye is pretty small in a case designed for black powder). I know sometimes we get fixated on a subject and need to know every theory, every physical characteristic of components interaction, and I can't help you there. I'm just a retired HD mechanic with mebbe 30 reloading experience (98% handguns) and I know fer sure, 38 special loads are safe to use in .357 brass (no detonation due to light loads of slow powder, no double charges, no too heavy bullets). I'd even venture to say any load you find in a manual for .38 Special will be safe in .357 Magnum brass...

[Thunder50]

JohndeFresno

IIRC, it was 13.7gr of AA #9. I was using a Denver Bullets 295gr lead alloy SWC, same bullet I used in my Ruger "silver hornpipe" super blackhawk.

The powder became lawn fertilizer when I got home.




edit-- new ww 44mag cases, fed 155 lpm primer. Gun wasn't brand new, but probably had less than a box thru it. Had just purchased it the weekend before. S&W 29 silhouette model. first time out shooting it.

[JohndeFresno]

JohndeFresno

IIRC, it was 13.7gr of AA #9. I was using a Denver Bullets 295gr lead alloy SWC...

I am not familiar with that bullet. .44? .45 caliber???

I don't think you are talking about .38/.357.

Running a VERY quick computation using a somewhat similar bullet (.430 300 gr. SWC WMEX 4027) for the S&W .44 Special and using 13.7 gr. AA#9, QuickLoad says:
Max SAAMI allowable pressure: 15,500 psi.
This load, with red warning flags - 22,856 psi.
True, the load fills only 67.6% of the case (per QuickLoad info) and burns only 67.99% of the powder out of a 2.5 inch Bulldog, providing 727 fps muzzle velocity. But you can see that the pressure is out of sight for a .44 Special.

Regardless of barrel length, you can see that the pressure is way over the top. AA# 9 is one of those powders that carries warnings due to uneven, as I understand it, pressure spike(s).

Even the much lighter Mt. Baldy .430, 250, MtBaldy LSWC Keith 429421, which is in my QuickLoad database, gives you 15,973 psi - flagged red by QuickLoad and over the top for the .44 Special allowable specs - using that AA #9.

I see in my reloading manuals that the writers suggest this particular powder for heavier bullets in magnum loads.

At any rate, this seems to me a very extreme case for the argument, providing you were loading that immense bullet with AA #9 into a .44 Special. It is just the wrong choice for lighter loads.

Man, I love that QuickLoad software. I understand the proviso of not just trusting one source or any "techno-geek gadgets," for that matter. But used in conjunction with other data, this software has saved me time, trouble, and has indeed steered me away from dangerous loads like the one above. I can't recommend the product enough for serious handloaders.

[Thunder50]

Super Blackhawk or S&W 29, both 44 magnums. Well within pressure limitations.

[JohndeFresno]

Super Blackhawk or S&W 29, both 44 magnums. Well within pressure limitations.

Wow. I have no answer.

[El Chivo]

John, are you saying a revolver can only take 15,000 psi?

Ok, what is that in copper units, 16,000?

It seems to me that factory ammo, ok for either rifles of handguns, would be in the 30,000 range, maybe 40,000. I have a hard time even finding a load in a book that's under 20,000.

Am I missing something?

[Hobie]

J miller

Brand new can of powder

Charge was way too low ,I found out later

Hardly any recoil when it blew, thing I noticed was the flash. More recoil on the first 5.

So not too much powder, too little. I weighed every charge and visually inspected powder level in each case.

May not convince you it can happen, but you will not ever convince me that it cannot. I still have the remains of the gun and remember that day well. I shot IHMSA quite a bit then and was quite meticulous in the assembly of the loads I was going to test for my "new" gun.

Did I miss the post where you told us what powder, cartridge, bullet, primer and so forth?

[JohndeFresno]

John, are you saying a revolver can only take 15,000 psi?...

No, El Chivo, I'm not saying it. These guys are:



I personally don't have the means to test or comment on pressures; I have to rely on the engineers for that.

The above represents the SAAMI limit for standard pressure .44's - look at "PMax," top center of the display. That is what I understood Thunder50 to be talking about. Then, he added the name of the handgun that failed.

As for C.U.P. - QuickLoad advises that PSI does not relate to C.U.P. with a warning not to use C.U.P. data as a reference. I can only go by what published tables would show for that older and less precise type of measurement.

[Hobie]

JohndeFresno

IIRC, it was 13.7gr of AA #9. I was using a Denver Bullets 295gr lead alloy SWC, same bullet I used in my Ruger "silver hornpipe" super blackhawk.

The powder became lawn fertilizer when I got home.

Thanks to JohndeFresno I found it.

[Griff]

Super Blackhawk or S&W 29, both 44 magnums. Well within pressure limitations.

Wow. I have no answer.

Well... as much as I'm loathe to say it, sometimes we make reloading errors. Sometimes we don't know the history of a gun and what it's been subjected to. There are a number of reasons things fail. What has happened in any particular case is difficult to say, after the fact.

I have an early 3rd Gen Colt SAA... several years ago I sent it off to a gunsmith friend to fix some end shake it had developed in over 20 years of cowboy action shooting. I got this gun new, have pretty much only shoot cowboy loads with it, both in BP and loads in the 800fps range. I did have a double charge of PB once, and bulged the original cylinder. It was replaced with a 2nd gen cylinder and fit bushing... It was this combination that had developed the end-shake.

I got the gun back about 4 weeks later with a note saying that the gunsmith had to replace the cylinder again because of stress cracks all over it. He said nothing was visible to the naked eye, he found them when he mangufluxed it. He surmised that it may never have come apart with my usual loads, but... He also said that they were probably there from when it was first machined from a .357 to a .45. I immediately sent off the other gun to be checked also.

[junkbug]

Elmer Keith believed detonation could occur with partial charges of slow smokeless rifle powder in bottle neck rifle cases.

http://elmerkeithshoot.org/GA/1982_10_C ... harges.pdf

[El Chivo]

Most of the internet postings I read attribute the problem to a stuck bullet or other obstruction. This I can see happening; a two-stage burn, with a stuck bullet and then the rest of the charge going off, like OS described. The term "detonation" makes it sound like a spontaneous explosion, and that's hard to believe.

I mean, what turns slow powder granules into explosive particles? Aren't slow powders slow because the granules burn slowly (from the outside in)? They're not slow because of their position in the case, they're slow due to the composition of the material.