So I don't muck up the Staccato thread I do this separately as a general Q about drop safety. My Q is that for the gun to fire when dropped I understand that the barrel would need to be reasonably close to vertical. So in that position, if it fires, is the problem a possible ricochet off the hard floor? The bullet splitting into pieces and spraying around? Or does the floor act as a barrel stoppage so the barrel splits/explodes? I am trying to understand the general physics of the problem.
Are you asking specifically about 1911's or guns in general?
What causes a dropped gun to fire varies greatly from gun design to gun design.
The firing pin overcoming the tension in the spring when the muzzle end impacts the ground is specific to the pre-Series 80 1911.
If you are talking about that particular scenario, which is somewhat rare but does happen, it's dependent partially on the surface it strikes and the type of bullet, but it tends to do what any other bullet would do if fired at a hard surface an inch or less away and either fragment or change directions and travel somewhat parallel to the hard surface it impacts. The thing about bullets though, in the words of my forensics instructor long ago, is "they do funny things."
I've never heard of a muzzle-down fall behaving like a barrel occlusion. It would be pretty unlikely for the gun to be positioned right to make a tight enough seal for that to happen.Originally Posted by CraigS
The aftermath photos that I've seen show where the bullet hit the floor. In every instance I've seen documentation of...and keep in mind it's been a handful of incidents...there's been a hard floor surface like tile over concrete. You see tile or the concrete itself has a chunk taken out of it and maybe some scattered damage from the now completely fragmented bullet. The fragments tend to do less damage because immediately smacking into a surface that hard tends to shed a lot of energy.
I've never seen documentation of it happening on something like, say, the second floor of a typical house. That's plywood with carpet and maybe a pad underneath. In that instance unless the bullet hits one of the supports for the floor, it'll most likely punch through the floor and stop somewhere in the first story. You'd be amazed at how little in a typical house will stop a handgun bullet.
Obviously if that scenario inside a residential structure happens, death or serious injury can result.
3/15/2016
Kev, good Q. I am thinking guns in general. Not really concerned w/ the mechanics of how it can happen w/ different trigger systems. Just trying to understand how dangerous a dropped gun firing could be.
One incident that's been discussed here several times involved a 1903 Colt that fell and discharged into a staffer for a gun magazine, killing him.
IIRC the pistol struck on the back of the slide, discharging upward.
Here's Ayoob's article on dropped gun inertial discharge and the gunwriter Steve Malloy.
https://www.athlonoutdoors.com/artic...ia-discharge/?
The way they land most of the time is barrel up, usually at an angle. Which can be immediately deadly.
3/15/2016
With a properly maintained 1911, the circumstances that make it discharge tend to involve impact on the muzzle end of the gun.
There are other guns through the years, like the SIG P220 I posted in the other thread, where an impact to the rear of the gun (hammer, striker plate, etc.) causes the discharge. The Colt Single Action Army is a good example of this. That's why most people carried it with the hammer on an empty chamber. S&W revolvers incorporated a "hammer block" and later a "transfer bar" to make it safe to carry the cylinder full.
As mentioned above, Steve Malloy was killed with when his Colt 1903 fell and discharged. He's not the first victim of this sort of thing. It's one of the reasons revolvers stayed in favor with police departments for as long as they did because many felt semi-automatics were "unsafe."
The S&W Model 39/59 was only drop safe when the safety was engaged, which is why it was advised by the factory back in the day to carry them only on-safe (they were completely safe carried in this manner). Dropping them on their muzzle or on their hammer would cause them to discharge with the safety was disengaged. The 2nd Gen S&W received a passive firing pin safety. When I started as a cop and the S&W 3rd Gen was being issued we were still taught to carry them "on-safe" at all times, which was a hold-over from the 39/59. There were still firearms instructors that had been brought up with the 39/59 who were convinced the 3rd Gen guns had to be carried "on-safe" even though S&W was selling the guns with a de-cock only option and DAO guns with no safety lever.
There is a thread here on the forum from a few years ago about various striker fired guns being tested for this with someone using a mallet. The result on quite a few is no discharge, but a dead trigger. It's probably worth digging up if you're interested in the topic.
Langdon's Beretta drop tests:
https://www.youtube.com/watch?v=9aQ_YNd35zk
https://www.youtube.com/watch?v=BzADdfWjv6I
Shadow 2s drops are dropping on hammer slamming it into firing pin with enough force to detonate primer.
The misses are Excerpts from American Handgunners circa 2000 article regarding the testing and selection process for the FBI SWAT 1911s.
Following several questions from the candidates to clarify nebulous specifications, a succession of five amendments were issued to RFP #6990, the last one coming on April 22, 1997. The most significant amendment was the deletion of a controversial requirement for a firing pin safety because Colt\'s Mfg. Co. holds a patent on the Series 80 firing pin safety. No other manufacturer could submit a gun with a firing pin safety without a license from Colt, a rather significant advantage for the Hartford gunmaker.
Once the firing pin requirement was dropped, testing began with each contender entering five pistols. The initial phase consisted of simply examining the pistols to see if they met the basic requirements. For instance, the specifications did not include a recoil spring guide rod. Wilson submitted guns with guide rods, so his pistols were returned for correction. Wilson removed the guide rods and resubmitted his guns.
Abusive Behavior
Meanwhile, the guns that were not randomly chosen for accuracy testing were relegated to the abuse test. The abuse test had two parts: a drop test and a throw test. During both, the guns could not discharge and the magazines could not dislodge from the weapons. Finally, the guns had to fire a full magazine after being dropped or thrown.
During the drop test, guns were dropped onto concrete from a height of 4 feet, landing three times on the muzzle and three times on the butt. The throw test was conducted at 15 feet with the guns heaved onto concrete, twice on the left side and twice on the right. "The guns were pretty beat up after that," Williams deadpanned. However, none of the primed empty cases in the chambers popped and none of the magazines came loose, so it was on to the "field suitability" test.
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