1911Tuner
Moderator Emeritus
Sorry, Dave. No video camera here. I may be able to talk Hunter into bringin' his down from Raleigh. I'll see what I can do.
Unintentional Discharge with 1911 in Public Bathroom
- Thread starter Bartholomew Roberts
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It should make it out of the barrel. It may and probably will stop dead at the concrete. The gas pressure in the barrel will drive the barrel UP and away from the bullet once the bullet stops. As you said, the slide will already be heading away from the bullet from the recoil. The pressure will act just like those air hog or water based kids rockets.
wally
Member
Maybe we should take up a collection so Tuner could rent a Photon hi-speed camera so we could have slow motion video.
'Tuner, maybe do a little kickstarter project.... http://www.kickstarter.com/
Or just call up local camera shops, find out if any have a high speed camera, and say "ok, you're GOING to want to come video this test we're doing."
Curiosity will bring them out with their gear.
Just don't forget to put lexan between the camera and the gun, don't want a fragment blowing a hole in some critical piece of that expensive camera.
Curiosity will bring them out with their gear.
Just don't forget to put lexan between the camera and the gun, don't want a fragment blowing a hole in some critical piece of that expensive camera.
1911Tuner
Moderator Emeritus
At this point in the plan, I don't think it'll be video tapeable.
(Is that even a word?)
The whole thing will be contained...either in a metal 30-gallon trash can or inside stacked tires. The only reason to have a camera along is to bear witness to the massive destruction...or the lack of it.
After thinking it through, I don't believe it'll amount to much.
But every so often, I'm wrong...so it will be contained.
(Is that even a word?)
The whole thing will be contained...either in a metal 30-gallon trash can or inside stacked tires. The only reason to have a camera along is to bear witness to the massive destruction...or the lack of it.
After thinking it through, I don't believe it'll amount to much.
But every so often, I'm wrong...so it will be contained.
wally
Member
I'm betting the bullet clearly makes it out of the barrel for a combination of at least three effects:
The air in front of the bullet will make a "jet" as the bullet moves tending to make space between the barrel and floor.
Every high speed video of bullets leaving a barrel I've seen shows some jets of hot gas exiting in front of the bullet which will also tend to make space between the barrel and floor.
In the ~100 microseconds it takes for peak pressure the barrel may already have bounced up some.
Actually I'd love to see high speed video because the barrel/slide bouncing up may have as much to do with popping the primer as the firing pin moving down -- the vector addition of the barrel/slide bouncing up and the firing pin still moving down, so it could actually be a bit off the floor before the primer pops.
If any of this is what really happens it adds a great deal of randomness as to the size and direction of any fragments because the angle will likely not be 90 degrees to the floor. Bigger the fragment, the greater the potential danger.
Maybe an Email to Mythbusters is in order
The air in front of the bullet will make a "jet" as the bullet moves tending to make space between the barrel and floor.
Every high speed video of bullets leaving a barrel I've seen shows some jets of hot gas exiting in front of the bullet which will also tend to make space between the barrel and floor.
In the ~100 microseconds it takes for peak pressure the barrel may already have bounced up some.
Actually I'd love to see high speed video because the barrel/slide bouncing up may have as much to do with popping the primer as the firing pin moving down -- the vector addition of the barrel/slide bouncing up and the firing pin still moving down, so it could actually be a bit off the floor before the primer pops.
If any of this is what really happens it adds a great deal of randomness as to the size and direction of any fragments because the angle will likely not be 90 degrees to the floor. Bigger the fragment, the greater the potential danger.
Maybe an Email to Mythbusters is in order
1911Tuner
Moderator Emeritus
Could be, but the slide itself will recoil on its own about a 10th inch, creating a space without the jet's help. That's why I want to do this experiment.
And the jet isn't so much compressed air as it is gas blowby getting around the bullet. I've seen high-speed videos comparing jacketed and lead bullets showing that a lead bullet of the correct hardness obturates and seals the bore much earlier...cutting the gas blowby drastically.
Then, there's the question as to whether the jet/blowby is enough to lift a 3-pound pistol to any significant degree. That's something that only a high-speed video can determine.
The main question...the one that prompts me to do this...Even if the bullet makes it out, is there enough residual velocity after slamming head-on into a concrete floor to present a real danger? On that one, I have my doubts.
I intend to do it with a jacketed bullet in any event.
RetiredUSNChief
Member
Come on, guys! Give me a little credit here! I know you all don't know me from Adam, personally, but trust me...this ain't rocket science and I'm certainly not proposing anything with tight tolerances here! Hobby tubes are perfectly fine and anybody who can't set up two in parallel, sufficient to serve as guide tubes on rods, must not have heard about using a spacer...like ruler marks or a short piece of 1X8 or 1x10!
At any rate, if I might make another suggestion here...
Use a micrometer to do barrel measurements first. Most barrel deformations are typically easily visible with the naked eye when viewed along the axis of the barrel, but a micrometer would give measurements people can see on paper.
At any rate, if I might make another suggestion here...
Use a micrometer to do barrel measurements first. Most barrel deformations are typically easily visible with the naked eye when viewed along the axis of the barrel, but a micrometer would give measurements people can see on paper.
1911Tuner
Moderator Emeritus
I'll do that, and thanks for the suggestion. I suspect that the barrel will bulge or "ring" to some degree since we're essentially creating a bore obstruction.
I intend to use just the slide and barrel to insure a dead straight drop. I'll add weight with casting ingots to try and approximate the recoil spring's in-battery resistance...but it may be a little tricky. A 16-pound spring's static preloaded resistance is around 8 pounds. I may only be able to find room for 4 ingots.
rocket science no.. and certainly easy, I was talking about easier.
Now to find long enough rods. I have a few sources where to look. I do currently already own stainless safety wire that can be pulled dead straight and run thru the plunger tube. I'd be done with it already if I owned a 1911 I was willing to drop on it's nose.
Now to find long enough rods. I have a few sources where to look. I do currently already own stainless safety wire that can be pulled dead straight and run thru the plunger tube. I'd be done with it already if I owned a 1911 I was willing to drop on it's nose.
marv
Member
Since the safety on a 1911 engages a notch in the slide, what kind of damage did that gun suffer when it ND'd. Or would the safety retain the slide, thereby making it a single shot? Inquiring minds want to know.
wally
Member
Go back to the original thread and look at the photo he posted. It appears the safety "jumped" the notch and hung the slide about halfways back. Would seem something must have broken.
1911Tuner
Moderator Emeritus
That wouldn't happen. If the safety was engaged, it would have stopped the slide in its tracks...even if something on the safety broke.
Which is part of the reason for my planned test. I want to see where the bullet will go when the muzzle hits the flo'.
I don't think the guy is tellin' the whole story. I gots me some suspicions. Oh, yes I does.
wally
Member
Did you look at the photo? here is a direct link, not sure it'll work ...
Slide is more like 3/4 back on a second look, safety "engaged" up on the serrations.
1911Tuner
Moderator Emeritus
Anybody can stage a photo to prove pretty much anything.
That didn't happen when the gun fired. Go ahead and take it to the bank.
That didn't happen when the gun fired. Go ahead and take it to the bank.
wally
Member
The original poster in ar15.com admits to doing something "stupid" and opens himself up for ridicule in the hopes of maybe preventing someone else from making the same mistake.
What's the point of faking a photo of the pistol afterwards?
What's the point of faking a photo of the pistol afterwards?
1911Tuner
Moderator Emeritus
Don't know...but that didn't happen when the gun fired with the safety engaged.
The slide would have driven the crosspin hard against the hole in the frame 90 degrees to the direction that it has to move to get it out of the frame.
And the slide would have stopped in its tracks. You can reach over the top of the slide and grasp it and push forward on it with about 10 pounds of force...and keep it from moving when it's fired. Some people who shoot thumbs forward have discovered that they've cause their pistols to short cycle by unknowingly pressing their thumbs against the slide. (And you can.)
The safety won't "hang" in the takedown position anyway. Try it. It'll either pop up to the ON position...or down to the OFF position.
Remove the plunger assembly so that you can get it to stay in the takedown position...then press the muzzle hard against a wall...and try to push the crosspin to the left. You'll see that it's in a pretty hard bind, and because only one side is being driven back...the pin is in a cattywampus bind with the holes.
Didn't happ'n, Cap'n.
There are a few things that the 1911 pistol flat can't do, and...like the myth of blowing up because it was out of battery when the trigger was pulled...this is one of them.
Maybe the stupid thing that was reported wasn't the stupid thing that happened?
Bugger picker hitting the bangswitch = lots more legal liability for discharge, than "the gun went off all by itself, officer, honest!!!"
OilyPablo
Member
Very much deeper than originally thought. Good analysis guys.
wally
Member
I've done a fair amount of testing on various pistols with primed, resized empties and its clear designers go to great lengths to insure that if the primer pops, the barrel and slide have at least some locking surface engagement to prevent out of battery firing. But I'd never say can't happen -- with so many guns out there the possibility of latent manufacturing defect (God knows I've got my share of defective out of the box should never have been shipped pistols), abnormal wear, or incompetent "repairs", the chance is small but non-zero.
Perhaps this failure to lock the slide by the safety is a quirky failure mode of MIM parts.
OilyPablo
Member
Here we go.
'Tuner, one other suggestion for your test. I'd love to see if the impact surface/floor makes a difference in whether a gun goes off. I wonder if you could drop first onto wood planks, then carpeted concrete, then bare concrete. I seem to recall some story about a rash of ADs when guys started dropping their guns on battleship decks; purportedly, muzzle-down drops onto dirt or wood barracks floors weren't sharp enough to cause AD's, but thick armor on the deck of battleships was so unyielding that it made the deceleration rapid enough to overcome FP spring resistance. Possibly apocryphal, but maybe worth a little validation?
The reason any of this would matter is that a muzzle-down discharge into concrete, while bad and loud and terrifying, is unlikely to get anyone killed. (I concur with your prediction that concrete will just splatter the bullet.) But if the gun will go off when dropped on a wooden floor, it's possible that someone might be standing beneath the floor on a lower story of a structure. And bullets will punch through wood while retaining lethal velocity. If a wooden floor impact will set off the gun, then the possibility of a full-scale tragedy becomes far more likely.
The reason any of this would matter is that a muzzle-down discharge into concrete, while bad and loud and terrifying, is unlikely to get anyone killed. (I concur with your prediction that concrete will just splatter the bullet.) But if the gun will go off when dropped on a wooden floor, it's possible that someone might be standing beneath the floor on a lower story of a structure. And bullets will punch through wood while retaining lethal velocity. If a wooden floor impact will set off the gun, then the possibility of a full-scale tragedy becomes far more likely.
1911Tuner
Moderator Emeritus
I've already conducted drop tests on various surfaces using primed cases. Wood/plank floor requires about 60% more height to go bang. Carpeted concrete...about 10%.
With a dead straight drop onto bare concrete, using just the slide and barrel...and a firing pin spring with moderate mileage...I got the primers to pop reliably at around 5.5 feet. Below that...around shoulder height for me....the bang/no bang rate was about 50/50. None popped when dropped from waist height. I'm 6'2" tall to put it in perspective.
Then, with an assembled gun, I tried dropping it in several realistic scenarios, from fumbled draw to wounded man to bouncing out of the holster/man on the run to just throwing the gun in the air and letting it spin. I never got the gun to fire on any surface, nor was I able to make it fire on a graveled road with a dead straight drop until I stood on a 6-foot ladder and dropped it from over my head.
The chances of dropping one accidentally in the real world and having it land straight onto the muzzle are slim. Certainly possible, but very slim. The loaded pistol tends to land muzzle up far more often when dropped from waist or shoulder height.
I also tried dropping it at a slight angle...estimated 15 degrees...and only got one ignition in 10 tries on a concrete surface from the ladder. Height...I'd estimate at 10 feet.
It's been a while, so these numbers may not be exact, but they're pretty close.
With a dead straight drop onto bare concrete, using just the slide and barrel...and a firing pin spring with moderate mileage...I got the primers to pop reliably at around 5.5 feet. Below that...around shoulder height for me....the bang/no bang rate was about 50/50. None popped when dropped from waist height. I'm 6'2" tall to put it in perspective.
Then, with an assembled gun, I tried dropping it in several realistic scenarios, from fumbled draw to wounded man to bouncing out of the holster/man on the run to just throwing the gun in the air and letting it spin. I never got the gun to fire on any surface, nor was I able to make it fire on a graveled road with a dead straight drop until I stood on a 6-foot ladder and dropped it from over my head.
The chances of dropping one accidentally in the real world and having it land straight onto the muzzle are slim. Certainly possible, but very slim. The loaded pistol tends to land muzzle up far more often when dropped from waist or shoulder height.
I also tried dropping it at a slight angle...estimated 15 degrees...and only got one ignition in 10 tries on a concrete surface from the ladder. Height...I'd estimate at 10 feet.
It's been a while, so these numbers may not be exact, but they're pretty close.
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