detonation in handguns with fast powders

[rhead]

Do not rule out the possibility of a skirt failure on the previous round leaving a partial obstruction in the barrel.

[olafhardt]

I have often thought that detonations occur all the time with small loads of fast powder. They just are too small to blow up the guns. These calculations support that idea. I am contemplating their possible contribution to pressure spikes

[scattershot]

I used to be skeptical of the detonation theory, believing instead that a double charge of powder was the culprit. If a 2.7 grain of Bullseye was doubled, it would only amount to 5.4 grains, hardly enough to blow up a pistol. I don't pretend to know what's going on, but it's just one more thing to think about.

[Whitespider]

If a 2.7 grain of Bullseye was doubled, it would only amount to 5.4 grains, hardly enough to blow up a pistol.

I'm not so sure about that...
Although 5.4 grains don't seem like a lot, it ain't about the quantity (grains), it's about the relative percentage... and strange things happen to burning rate when pressures increase much beyond the design limits of the propellant.
If you figure that 3.5 grains is the safe maximum, 5.4 grains is a 40% increase over that‼
Think about a 40% increase in other cartridges. For example, that would be like loading your .44 Magnum with 30 grains of 2400 or H110‼ Or 80 grains of 4350 in your .30-06‼

[AbitNutz]

Many times a handgun Chernobyl has more than one cause. Perhaps I did double charge it but also what if I seated the longer HBWC backwards by accident, as well as one astute member pointed out. Or the skirt separated on the first bullet leaving some chunks in the bore, as another member mentioned. Then the second round fired was an over charge?

I guess what I'm going back to is that I'm never going to find out for sure. All I can do is make sure I put in to place a protocol that makes it almost impossible to happen again.

[35remington]

Supposing that powder just "lays there" in the case and allows primer flash to "ignite it at both ends" is an extremely weak understanding of how primers work to ignite pistol powders.

This is not how events happen, nor does this contribute to blown up guns

[35remington]

Ask yourself why "detonations" of fast powder happen supposedly only in pistols.....when it is extremely common to shoot very light charges of Bullseye in rifle cases and you never hear of problems.

It ain't the powder. It's the goof running the powder measure and loading the ammo.

[WallyM3]

"I'm not so sure about that...
Although 5.4 grains don't seem like a lot, it ain't about the quantity (grains), it's about the relative percentage... and strange things happen to burning rate when pressures increase much beyond the design limits of the propellant.
If you figure that 3.5 grains is the safe maximum, 5.4 grains is a 40% increase over that‼
Think about a 40% increase in other cartridges. For example, that would be like loading your .44 Magnum with 30 grains of 2400 or H110‼ Or 80 grains of 4350 in your .30-06‼"

Richard Lee lists 5.7gr B'eye as max for .357 Magnum, more than twice the 2.7gr. load the WC 38 Special. Not too much difference between a Model 10 and a Model 13 S&W.

[Elkins45]

Ask yourself why "detonations" of fast powder happen supposedly only in pistols.....when it is extremely common to shoot very light charges of Bullseye in rifle cases and you never hear of problems.

It ain't the powder. It's the goof running the powder measure and loading the ammo.

What about rifle shooters who blame Secondary Explosion Effect (SEE) for blown up guns? A Google search for the term finds a whole bunch of instances where small charges of fast pistol powders are blamed for blowing up rifles.

I dont know if the phenomenon is limited to pistols, but the blame isn't.

[olafhardt]

Note: in the 30 06 I used a powder charge of 30 grains.reducing this reduces pressure. Increasing it could change detonation conditions. Powder characteristics were not considered because I have no idea how to. I picture the powder being caught up in a cloud of very turbulent, very hot cloud of primer gas and debris. The reason I went threw this was I think they various detonation theories I have read don't make a lot of sense. This theory shows that the powder only has to burn. What makes it burn so much faster, I have no idea, maybe it does "detonate". I have no conception of what the difference between "burn real fast" and" detonate"is. I also don't trust organic nitrates to be thoroughly predictable especially in high temperatures and pressures.

[35remington]

Wrong effect, Elk. SEE is. specifically, reduced loads of SLOW rifle powder blowing up guns. Does not happen with very small charges of pistol powders in rifles.

Ever. You have to wonder why.

[MtGun44]

IMO high pressure events are double charges. I am extremely skeptical of
the claims for unusual burning of normal pistol powders the "somehow" magically
create double pressure.

Occam's Razor - simplest solution which requires no magic and relies on one of the
most reliable forces in nature - human error.

Many folks would much rather believe in magic than believe that they made an error
when they were trying their best not to.

Bill

[Bullwolf]

I used to be skeptical of the detonation theory, believing instead that a double charge of powder was the culprit. If a 2.7 grain of Bullseye was doubled, it would only amount to 5.4 grains, hardly enough to blow up a pistol. I don't pretend to know what's going on, but it's just one more thing to think about.

I'm not so sure about that...
Although 5.4 grains don't seem like a lot, it ain't about the quantity (grains), it's about the relative percentage... and strange things happen to burning rate when pressures increase much beyond the design limits of the propellant.
If you figure that 3.5 grains is the safe maximum, 5.4 grains is a 40% increase over that‼
Think about a 40% increase in other cartridges. For example, that would be like loading your .44 Magnum with 30 grains of 2400 or H110‼ Or 80 grains of 4350 in your .30-06‼

Not trying to single you out here Whitespider, Just replying to your post as my reply seems to fit here the best.

The Hercules Powder company did some testing regarding this very subject regarding the use and potential of overcharging Bullseye with 38 wad cutters some years back.

Here's a reprint of the original article from American Handgunner magazine.

This subject has become a something of a re-occurring theme on the board every few months. Typically when it rears it's head again, this article gets re-pasted. Since no one else has added it yet, I am doing so here.

[click on the thumbnail images to make them larger]







Others reading this thread for the first time may find this information on the subject to be extremely educational.




- Bullwolf

[WallyM3]

It's telling me an otherwise properly loaded double-charge (5.4gr. B'eye) will not destroy a modern Model 10 or 14 type, since a nearly identical Model 13 is rated for 357 Magnum (35,000psi). Not wholesome, but probably not catastrophic.

Cram the bullet down into the case...then you could get hurt.

[Old Caster]

If light loads of fast powder could detonate in pistols, virtually every bullseye shooter that has been around shooting for 50 + years like me and all my friends would have had it happen. We are always trying to see how light a load we can shoot in timed and rapid fire to stay away from recoil and the only thing that keeps us from going even lighter is lack of accuracy at too slow of a speed. In some guns, this is around a bit over 500 fps, specifically 32 long with a 100 grain HBWC.

[wmitty]

Doesn't the detonation of a high nitroglycerin content smokeless powder require a high brisance initiator, such as a blasting cap or detonating cord?

[mpbarry1]

very intesting thread. thanks for the discussion. I just had a friend warn me about this, but I am a skeptic. I appreciate the info.

[Larry Gibson]

Bullwolf's excellent post, #33, is the answer.

A small amount of Bullseye such as 2.7 gr just does not have the potential energy to cause the destruction shown. Ask any chemist familiar with such. This has been discussed numerous times including SEE with all the usual myths brought up regarding "detonation". Detonation of smokeless powders is not a proven theory but double and triple charging of cases or using the wrong powder is proven.

Many years ago I investigated several "blowups of PPC revolvers using the 2.7 gr load with WCs of both Bullseye and 700X. After bulling several hundred bullets with kinetic bullet pullers myself and 2 others found 3 additions cartridges with overloads (2 - 2.5 times as much) from 2 different batches. The loads had all been loaded on the same type of inline progressive press that is addressed in the Handloader article. That press was very popular at the time but was discontinued because of the overload problems. With any progressive press, even the new ones of today, of any make it is easy to get a double or even a triple charge of powder if you aren't paying attention (most often getting interrupted) or when clearing a jam or have miss a step like not putting a bullet in a case.

It is human nature to want to blame something else when most often the fault lays with ourselves. The OP may have "thought" he didn't double charge a case with his progressive press but he most likely did. I have the same press and have done it myself when distracted, not paying attention of miss putting a bullet on a case for seating. When restarting from an interruption or when clearing a jam or a case w/o a bullet or powder in it is all to easy to double charge a case. I have seen others do it too many times to believe otherwise. I also have double charged cases when clearing a jam on my auto advancing progressive press. When I get interrupted or am clearing a jam I now remove and clear all unloaded cases from all the stations and simply start over. I have kept myself out of trouble more than once by following that simple caution.

Larry Gibson

[243winxb]

Don't do this. Fill a 357 mag case with Bullseye powder. Put a card wad over top, light crimp. Drip candle wax to seal. On firing, you may blow your revolver up or think you did.