How do Revolvers Kaboom?
- Thread starter RougeLeader
- Start date
Again, the shooter standing next to me locked up his Model 66 when he pulled the trigger on a round with no powder. Because time is not a factor to most reloaders there is no reason to waste my time explaining what could have happened had the bullet made it past the forcing cone and then stopped in the barrel.
And then there is the other time factor, the primer is fast, with a slow burning powder the primer can plug the barrel with the bullet. With the plugged barrel there is a chance the bullet can not move out of the way fast enough and I would guess the pistol would then be rendered scrap.
I am the fan of the jump start, I want my bullets to hit the rifling 'a-running'. I am not entertained by the ideal the bullet could have a difficult time getting started.
F. Guffey
I have no data to back this up,so it is opinion.
I suggest we discern between catastrophic blow ups,and just ruining the gun.
There also,at least in theory,isolated anomalities. For this I mean something like a flash over detonation. These may be "I can't prove it did or did not happen,but I don't believe I used the wrong powder,etc"
Actually blowing up the gun is seldom about pushing the max load,or the max load plus a little.
If a powder measure is functioning properly,the one or two or three tenth grain variation is not going to blow up a gun.
If we are starting with a sound,undamaged gun,not in any particular order:
Using the wrong powder
A double or triple load
A bore obstruction.I would include a mis-indexed cylinder here,and a no-powder squib load leaving a bullet in the bore
In some cases,maybe defective brass failure.This would more often be in a semi-auto.
I am NOT saying pushing the max or max + will cause no problem. A cylinder can stretch or swell a bit before it blows. This may show up as hard extraction.
Frame scan stretch,end play increases,cranes become misaligned,top straps can gas cut....
Pushing or exceeding limits can turn a fine handgun to junk in short order.
But to blow it up... It may be Bullseye was accidently used instead of 2400.
SO...only one powder on the bench,read the recipe for the load,read the label on the powder canister,twice. Out loud is best. Use original,labeled containers(maintain traceability)
OOPS!Powder measure is half full from last time! I dump it on the lawn. That hurts!. Incentive to not leave powder in the hopper.
Avoiding squibs and double charges: I get it that some powders are attractive because they are economical.Bullseye is an example. Low dosage powder. Its a good powder,but I prefer to sacrifice some economy for load density.I prefer a bulky enough charge that a double charge is impossible or at least very noticeable.
For a manual press,visual powder level inspection before seating. For progressive presses,a powder cop die or some other failsafe is good.
The most common bore obstruction is a squib. If you drop a hammer without a boom and recoil,stop. Make sure the bore is clear.Captain obvious says "Don't look in the muzzle".A pencil can work.
With those precautions,you are not likely to blow one up.
If we load to 90%or 95%,our guns will last longer than if we load to 100% or 105% of max.(And nothing wrong with 70%)
And lets not forget,not all guns are equal. While a Charter Arms Bulldog 44 spl is a perfectly good gun,you might scatter one shooting loads that an N-frame S+W or a Ruger Blackhawk can handle. Cylinder wall thickness nan get quite thin,especially at the cylinder bolt latch notches.
I suggest we discern between catastrophic blow ups,and just ruining the gun.
There also,at least in theory,isolated anomalities. For this I mean something like a flash over detonation. These may be "I can't prove it did or did not happen,but I don't believe I used the wrong powder,etc"
Actually blowing up the gun is seldom about pushing the max load,or the max load plus a little.
If a powder measure is functioning properly,the one or two or three tenth grain variation is not going to blow up a gun.
If we are starting with a sound,undamaged gun,not in any particular order:
Using the wrong powder
A double or triple load
A bore obstruction.I would include a mis-indexed cylinder here,and a no-powder squib load leaving a bullet in the bore
In some cases,maybe defective brass failure.This would more often be in a semi-auto.
I am NOT saying pushing the max or max + will cause no problem. A cylinder can stretch or swell a bit before it blows. This may show up as hard extraction.
Frame scan stretch,end play increases,cranes become misaligned,top straps can gas cut....
Pushing or exceeding limits can turn a fine handgun to junk in short order.
But to blow it up... It may be Bullseye was accidently used instead of 2400.
SO...only one powder on the bench,read the recipe for the load,read the label on the powder canister,twice. Out loud is best. Use original,labeled containers(maintain traceability)
OOPS!Powder measure is half full from last time! I dump it on the lawn. That hurts!. Incentive to not leave powder in the hopper.
Avoiding squibs and double charges: I get it that some powders are attractive because they are economical.Bullseye is an example. Low dosage powder. Its a good powder,but I prefer to sacrifice some economy for load density.I prefer a bulky enough charge that a double charge is impossible or at least very noticeable.
For a manual press,visual powder level inspection before seating. For progressive presses,a powder cop die or some other failsafe is good.
The most common bore obstruction is a squib. If you drop a hammer without a boom and recoil,stop. Make sure the bore is clear.Captain obvious says "Don't look in the muzzle".A pencil can work.
With those precautions,you are not likely to blow one up.
If we load to 90%or 95%,our guns will last longer than if we load to 100% or 105% of max.(And nothing wrong with 70%)
And lets not forget,not all guns are equal. While a Charter Arms Bulldog 44 spl is a perfectly good gun,you might scatter one shooting loads that an N-frame S+W or a Ruger Blackhawk can handle. Cylinder wall thickness nan get quite thin,especially at the cylinder bolt latch notches.
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RougeLeader,
Brass is more plastic (malleable) and less elastic than steel. When a charge gets high enough, cases can resist ejection because the steel has expanded beyond the yield point of the brass but not beyond its own yield point, so it has then returned to its own original shape afterward, thereby clamping the expanded, less elastic brass in place. Many of the old-timers depended on this for revolver load development (read anything by Elmer Keith on load development). They would load up to the point the cases began to resist ejection, then back the charge weight down 5%.
The above is unique to revolvers because mushroomed and flattened primers and other pressure signs often fail to appear in revolvers before sticky ejection does. the steel is thinner at some parts of the chamber than others, so resistance to ejection is treated as a revolver pressure sign and therefore an indication you should back down. If you do not, but instead keep increasing the charge weight, the steel will give way first where it is thinnest, as FITASC's photos showed.
The reasons old load data are suspect are several. First, many old manual authors did not use pressure testing at all, instead of looking for pressure signs in a particular production firearm whose chamber(s) might be looser than others, and therefore needing more powder to reach a pressure sign. Moreover, pressure signs on a case usually tell you more about what the case can tolerate than what the gun can tolerate, the stick ejection being an exception. Second, manufacturers of and formulations for powders can and do change over time. An attempt is made to keep a new powder compatible with the original, but that may not always be exact. Almost all primer formulations have changed in some measure since 1989, and primers can have some effect on pressure. Many cartridge cases have at least slightly different capacities than they did even a decade ago due to outsourcing and changes in plants and tooling, forcing loads to be worked up again. Pressure measuring has advanced immensely since old data was developed, and now, instead of just a peak value, the whole pressure curve is revealed and in some instances, this has resulted in anomalies being identified that has changed load data. Probably the most notable was the warning from Alliant issued July 25, 2008, to stop loading Blue Dot powder in .357 Magnum with 125 grain bullets and to stop loading it in the .41 Remington Magnum at all. Old load data often has these loads Alliant says can be hazardous.
You are right about the time frame of firing events. Years ago, H.P. White Laboratories found they could not detect movement in a bullet before pressure reached 10,000 psi, despite bullet pull being only tens of pounds. That high number was due to the dynamics of the event. In the quarter millisecond or so it takes to go from primer pressure to 10,000 psi, the inertia of the bullet plays a significant roll in limiting its acceleration. Yet, if you fire just a primer with no powder, you can unseat a bullet into the throat of the gun. It's just that it doesn't happen as quickly. Given enough time, everything equilibrates toward steady-state behavior.
Brass is more plastic (malleable) and less elastic than steel. When a charge gets high enough, cases can resist ejection because the steel has expanded beyond the yield point of the brass but not beyond its own yield point, so it has then returned to its own original shape afterward, thereby clamping the expanded, less elastic brass in place. Many of the old-timers depended on this for revolver load development (read anything by Elmer Keith on load development). They would load up to the point the cases began to resist ejection, then back the charge weight down 5%.
The above is unique to revolvers because mushroomed and flattened primers and other pressure signs often fail to appear in revolvers before sticky ejection does. the steel is thinner at some parts of the chamber than others, so resistance to ejection is treated as a revolver pressure sign and therefore an indication you should back down. If you do not, but instead keep increasing the charge weight, the steel will give way first where it is thinnest, as FITASC's photos showed.
The reasons old load data are suspect are several. First, many old manual authors did not use pressure testing at all, instead of looking for pressure signs in a particular production firearm whose chamber(s) might be looser than others, and therefore needing more powder to reach a pressure sign. Moreover, pressure signs on a case usually tell you more about what the case can tolerate than what the gun can tolerate, the stick ejection being an exception. Second, manufacturers of and formulations for powders can and do change over time. An attempt is made to keep a new powder compatible with the original, but that may not always be exact. Almost all primer formulations have changed in some measure since 1989, and primers can have some effect on pressure. Many cartridge cases have at least slightly different capacities than they did even a decade ago due to outsourcing and changes in plants and tooling, forcing loads to be worked up again. Pressure measuring has advanced immensely since old data was developed, and now, instead of just a peak value, the whole pressure curve is revealed and in some instances, this has resulted in anomalies being identified that has changed load data. Probably the most notable was the warning from Alliant issued July 25, 2008, to stop loading Blue Dot powder in .357 Magnum with 125 grain bullets and to stop loading it in the .41 Remington Magnum at all. Old load data often has these loads Alliant says can be hazardous.
You are right about the time frame of firing events. Years ago, H.P. White Laboratories found they could not detect movement in a bullet before pressure reached 10,000 psi, despite bullet pull being only tens of pounds. That high number was due to the dynamics of the event. In the quarter millisecond or so it takes to go from primer pressure to 10,000 psi, the inertia of the bullet plays a significant roll in limiting its acceleration. Yet, if you fire just a primer with no powder, you can unseat a bullet into the throat of the gun. It's just that it doesn't happen as quickly. Given enough time, everything equilibrates toward steady-state behavior.
USSR said:
Agree 100%. I load with H110 and 2400 in 357, 44 , and 460 mag. You will never blow up a gun using H110 as overcharging the case is almost impossible but you can ABSOLUTELY blow up a gun with overcharging 2400 powder. Guys that load mouse fart loads are especially vulnerable. This is why I have a dedicated LED light that shines directly into my charged casing in my Dillon 650, I load slow and visually verify each charge.
I took him to mean the opposite: that appropriate and correct 2400 charge weights in non-magnum cartridges are so much more than the fast or medium speed powders that are much more commonly used in those cartridges that many people would look at the number and say it was too high, not realizing that it is OK for 2400, because 2400 is not Bullseye or Unique.
For example, Lyman 49 has 9.4 grains 2400 for standard pressure .38 Special and a 158 grain XTP. Unique is 5 grains. Someone who'd never thought to use 2400 in that cartridge might think 9 grains was crazy, but it's not.
RougeLeader
Inactive
Exactly. I chose 2400 as it meters quite well and requires a large powder charge compared to Bullseye or HP-38. To me this is advantageous as the larger powder charge is easier to see in the case and easier to detect when weighing finished rounds. I also just like how it performs, even though it does burn dirty.
H110 I can understand with the magnum rounds. I personally wouldn't want to try it in 38 Special. Just my preference.
H110 I can understand with the magnum rounds. I personally wouldn't want to try it in 38 Special. Just my preference.
Did you chrono them? How is accuracy?
I was doing something kinda/sorta similar yesterday: loaded and shot some 170 and 180 grain jacketed bullets in .357 with not much over starting charges of 4227. Still enough to come close to the base of the bullet, so max must be heavily compressed.
Average velocity was about 875 FPS. Considering that there is very little room for the powder charge to slop around, I was surprised that the chrono showed quite a large extreme spread. (Like, 100 FPS large!)
Despite that, I shot a couple of good (for me) groups in slow fire. Recoil and blast were mild for .357, but certainly more than a .38 target load, so wouldn't be great for rapid fire. I wanted to know if my revolver liked long bullets, and I guess the answer is "yes." Kinda pricey for plinking ammo, but I don't get to the range that often, so I feel I can't afford to shoot cheap ammo! It's a pity that I have a couple thousand cheap bullets that aren't really worth my time. Should have just bought 600 XTPs.
I was doing something kinda/sorta similar yesterday: loaded and shot some 170 and 180 grain jacketed bullets in .357 with not much over starting charges of 4227. Still enough to come close to the base of the bullet, so max must be heavily compressed.
Average velocity was about 875 FPS. Considering that there is very little room for the powder charge to slop around, I was surprised that the chrono showed quite a large extreme spread. (Like, 100 FPS large!)
Despite that, I shot a couple of good (for me) groups in slow fire. Recoil and blast were mild for .357, but certainly more than a .38 target load, so wouldn't be great for rapid fire. I wanted to know if my revolver liked long bullets, and I guess the answer is "yes." Kinda pricey for plinking ammo, but I don't get to the range that often, so I feel I can't afford to shoot cheap ammo! It's a pity that I have a couple thousand cheap bullets that aren't really worth my time. Should have just bought 600 XTPs.
I don't think 4227 burns well at ANY pressure. 
Even in max loads in .357, I see a little trail of breadcrumbs down the barrel if I peek in before knocking it around too much. But it has a good reputation for accuracy. Despite what my manuals say, in my hands it always seems to lag behind 2400 in velocity.
Like 2400 and, as you say, UNLIKE H110, it seems to be safe to download it considerably without deadly squibs, if you want to burn more money and have a fuller case than a faster powder. Hodgdon has data for it in .38 Special standard pressure and +P. You won't find H110 in either of those listings!
Even in max loads in .357, I see a little trail of breadcrumbs down the barrel if I peek in before knocking it around too much. But it has a good reputation for accuracy. Despite what my manuals say, in my hands it always seems to lag behind 2400 in velocity.Like 2400 and, as you say, UNLIKE H110, it seems to be safe to download it considerably without deadly squibs, if you want to burn more money and have a fuller case than a faster powder. Hodgdon has data for it in .38 Special standard pressure and +P. You won't find H110 in either of those listings!
El Paso Joe
New member
Once - in what seems a very long time ago - there was a gun writer named Skeeter Skelton. Wrote for Shooting Times as I recall. In one of his missives he recounted loading a number of rounds and then leaving the setup in place for a couple of weeks or so and then finishing out the rest of the loads. The results he reported was that in the rounds loaded later the powder had degraded. One round would pop and fizzle and the next would wake up folks in the next county. Wolley booger was the term he used. Any thoughts on this?...
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Quote:
cecILL wrote:
The case just holds the propellant. It would explode without the cylinder/chamber.
Actually, it would not.
Ignite the primer in an unsupported case and once the pressure inside the case reaches the level to overcome the friction between the bullet and the case wall (which, ignoring some effects of dynamic friction, is the same pressure required to seat the bullet in the first place so you know it's not very high), the bullet would pop out and relieve the pressure.
To get an unsupported case to explode, you have to restrain the bullet's movement when you ignite the primer.
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Had ONE 45 ACP with 3.5 Bullseye go off in the press. No restrictions, no die in that station. Case Blew apart. Left sideways imprint of bullet in ceiling. Just a small dent showing lube grooves. Case looked like a peeled banana.
David
Quote:
cecILL wrote:
The case just holds the propellant. It would explode without the cylinder/chamber.
Actually, it would not.
Ignite the primer in an unsupported case and once the pressure inside the case reaches the level to overcome the friction between the bullet and the case wall (which, ignoring some effects of dynamic friction, is the same pressure required to seat the bullet in the first place so you know it's not very high), the bullet would pop out and relieve the pressure.
To get an unsupported case to explode, you have to restrain the bullet's movement when you ignite the primer.
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Had ONE 45 ACP with 3.5 Bullseye go off in the press. No restrictions, no die in that station. Case Blew apart. Left sideways imprint of bullet in ceiling. Just a small dent showing lube grooves. Case looked like a peeled banana.
David
Reloaders have formed a few bad habits, some have gone to sizing loaded ammo in a body die, There is a chance the powder trickled down through the flash hole and filled the area in front of the primer meaning when the primer was seated there was no room for it.
Bad Habit: There is a chance powder in the case could have trickled down through the flash hole and filled the primer meaning there is no room for the primer to move forward when seating. We had a member blow his thing off the handle of his inertia bullet puller. For the most part the accident was blamed on the use of a shell holder. No one considered the sudden stop of the hammer against the concrete drive could seat the primer and then cause a slam fire. The problem was given a lot of attention because he was pulling bullets in a crowd.
There was no way the shell holder in an inertia puller puller could slide over on top of the primer except on the smallest of cases. When pulling bullets on the smallest of cases use 'o' rings to center the case.
F. Guffey
Jim Watson
New member
Speer once built a single shot "cylinder" with pizeo pressure transducer for a .357 revolver. So it had all characteristics of the original gun, ignition, chamber, gap, and forcing cone, just for one instrumented shot at a time.
They found that the maximum pressure occurred before the bullet was out of the cylinder.
As shown, catastrophic failure of a revolver will fragment the cylinder and blow out or bend the topstrap. This usually takes a fast-for-slow powder error or a double charge.
Elmer Keith blew up more than one revolver pushing loads with old No 80 powder before 2400 was available. He got them fixed, too. A new cylinder, the frame straightened and a new topstrap welded in, and they were ready to go again.
Lesser pressure excursions will "jug" the chamber, or just bulge the thin spot under the cylinder stop notch. A small bulge will not be obvious except that extraction from that chamber becomes difficult or impossible.
Overloading short of "grenade" level will beat the gun to junk. I know one guy who wore out two S&W M10s with .38 Special +P (In practice and competition, many many more rounds than one poster's demonstration with a few hundred rounds.) and one author wore out a couple of Chief's Specials with full power standard pressure .38s. A friend shot heavy loads in a .45 Ruger until the forcing cone split.
They found that the maximum pressure occurred before the bullet was out of the cylinder.
As shown, catastrophic failure of a revolver will fragment the cylinder and blow out or bend the topstrap. This usually takes a fast-for-slow powder error or a double charge.
Elmer Keith blew up more than one revolver pushing loads with old No 80 powder before 2400 was available. He got them fixed, too. A new cylinder, the frame straightened and a new topstrap welded in, and they were ready to go again.
Lesser pressure excursions will "jug" the chamber, or just bulge the thin spot under the cylinder stop notch. A small bulge will not be obvious except that extraction from that chamber becomes difficult or impossible.
Overloading short of "grenade" level will beat the gun to junk. I know one guy who wore out two S&W M10s with .38 Special +P (In practice and competition, many many more rounds than one poster's demonstration with a few hundred rounds.) and one author wore out a couple of Chief's Specials with full power standard pressure .38s. A friend shot heavy loads in a .45 Ruger until the forcing cone split.
Don P. I agree. I have a few shell holders that do not have holes in the center, they are used for swaging bullets, I can not think of a situation where a reloader would decide to seat primers with a flat shell holder while the case was in a sizing die.
And then there are shell holders with slots and shell holders without slots. My shell holders without slots seem to protect me from myself. If the primer is not seated the case can not be removed from the shell holder. Most of the shell holders without slots are used with cases for auto loading.
F. Guffey