Heads up! MYTHBUSTERS season premiere tonight at 9 Eastern!

[Forbin]

Oh yeah, silver bullets - some of the gun magazines tested this one in the past. The thing is, silver shrinks when it cools (as Kari mentioned). If you cast the bullet in a standard mold, that means you get a bullet that's undersized for the bore of the gun. That means gas escapes around the bullet, the bullet doesn't engage the rifling as deeply, and the bullet may even wobble as it flies. None of these things are good for accuracy.

Come to think of it, sliver is harder than lead and/or copper (yes/no?), in which case engaging the rifling in the barrel may cause more drag on the bullet than normal.

 

[Christopher]

^So could you compensate by using a bigger mold to cast the silver bullets?

 

[Trekker4747]

Quick draw reaction time: This is so much like the kendo myth from last week. And they're making the same misinterpretation, assuming it means that reacting is faster than initiating. In this case, the movie situation where the bad guy draws first and the good guy gets the shot first, the idea isn't that reaction time is always faster; the idea is that the good guy is more skilled, has faster reflexes, and is a bigger badass than the villain. It's always cooler to win when you're at a disadvantage.

Well, to be fair the "reality" of what's happening in the movie (good over evil) is different than the implication of what's happening. Pretty much all of the Hollywood myths they test can be waved away with saying, "You missed the point, the good guy's stunts ALWAYS work!"

Anyway I also noticed in the slow-mos of Kari's "faster reaction time" that it looks like she shoots the gun before it was fully pointed forward, I think a degree of accuracy needed to be put into this on if "getting the shot off first" would have even worked to take down the other guy.

The discrepancy between the Junior team's attempts working and Jamie/Adam's "real word" testing could be chalked up to the difference between reacting to a light simply coming on and reacting to a movement (which may be too subtle to notice quickly enough.)

I really don't think the "running out of bullets" thing needed to be tested. Not even in a "to prove the point to people" sort of way. I'd hope most people are smart enough to realize that guns don't come with a God Mode/Unlimited Ammo Cheat.

 

[Lonemagpie]

True Lies automatic weapon on stairs: Not surprising this didn't work. Nothing about that horrible movie made any sense anyway. And it stands to reason that weapons would be designed not to go off if bumped.

They should have tried that with an early model British Army issue SA-80 from the late 80s/early 90s - the L85A1 - which absolutely would go off if dropped on its butt-plate, even with the safety on! (Prompting several expensive recalls and redesigns)

It couldn't have kept firing as went, like in True Lies, though - for extra shits and giggles it was very prone to jamming when set on auto, and the magazine release stuck out to catch on clothes, so that the clip would drop out at inconvenient moments. The whole thing was a Johnny English scene waiting to happen...

 

[Forbin]

^So could you compensate by using a bigger mold to cast the silver bullets?

Yup. You'd only have to calculate the shrinkage and create a mold the correct amount larger. That only leaves the question about how hard the silver is in terms of fitting into the barrel. Lead (and copper jackets) are soft enough that the bullet squeezes itself into the rifling and seals the barrel, so all the expanding gas goes into pushing it. If a bullet is too hard with no give, it could jam in the barrel and cause the barrel to rupture.

 

[Christopher]

Well, to be fair the "reality" of what's happening in the movie (good over evil) is different than the implication of what's happening. Pretty much all of the Hollywood myths they test can be waved away with saying, "You missed the point, the good guy's stunts ALWAYS work!"

No, that's not what I'm saying. It's not about "stunts" and luck going the hero's way; the idea is that the hero wins because he's more skilled than the competition, because he's the best there is. It's not meant to be a fight between two people of equal skill levels. The idea is that the hero earns the victory by being faster, more accurate, better-trained.

Anyway I also noticed in the slow-mos of Kari's "faster reaction time" that it looks like she shoots the gun before it was fully pointed forward, I think a degree of accuracy needed to be put into this on if "getting the shot off first" would have even worked to take down the other guy.

It's also very strange to me that they seemed to base it on only a single trial per team member. It should've been an average of multiple trials.

The discrepancy between the Junior team's attempts working and Jamie/Adam's "real word" testing could be chalked up to the difference between reacting to a light simply coming on and reacting to a movement (which may be too subtle to notice quickly enough.)

That's not the point. The point is that we can't know whether that's the case or not because the two parts of the experiment were tested by different people. Science isn't about guessing the reasons for things, it's about finding out for sure. If two experiments differ in two simultaneous ways, there's no way to know which of those differences was responsible for the difference in the results, so it's a crappy experimental design. You're supposed to isolate each variable, change only one thing at a time, so that you know for sure that that's the reason for the difference. It could be that the difference in results was due to the difference in situations, but there's no proof of that because the two situations were tested by different groups of people, and the difference could've been in the people instead. This is simply not how you do science. The Mythbusters' standards have really gone to pot.


Another thing that bugged me was the "shooting two guns" retest (that's the one I forgot about before) -- when they shot at two separate targets, they calculated their accuracy just by adding up the total score of both targets. They should've divided that result by two to get the average accuracy per target.

 

[Redfern]

I was just talking with my cubile neighbor who owns a rather extensive gun collection and I asked him about the "True Lies" situation. I noticed as presented, it appeared they ran a mere two tests, dropping the gun down the stairs. They may have done more, but as edited for the final broadcast, it looks like they did it only twice. Two drops and "Busted!" Sorry, that's just not enough to make the call. They should have done that at least ten times, maybe more.

Anyway, back to my co-worker. The has a "Mac-10" I believe he called it and he claims they are quite prone to a condition called "slam firing" and it has even happened to him. He popped the magazine into his gun one time and the accursed thing emptied all the rounds, bullets whizzing mere inches from his ear! Now, I've known this co-worker for 20 years and I have no reason to doubt his honesty. He's quite serious about his weapons. If he says a certain weapon is prone to certain conditions (such as "slam firing"), I believe him. On the other hand, you guys don't know me from Adam, so I won't blame you if you think I am making up a fish tale.

Sincerely,

Bill

 

[Lonemagpie]

Anyway, back to my co-worker. The has a "Mac-10" I believe he called it and he claims they are quite prone to a condition called "slam firing" and it has even happened to him. He popped the magazine into his gun one time and the accursed thing emptied all the rounds, bullets whizzing mere inches from his ear! Now, I've known this co-worker for 20 years and I have no reason to doubt his honesty. He's quite serious about his weapons. If he says a certain weapon is prone to certain conditions (such as "slam firing"), I believe him. On the other hand, you guys don't know me from Adam, so I won't blame you if you think I am making up a fish tale.

Sincerely,

Bill

The full-auto MAc-10 fires from an open bolt, which makes it vulnerable to slam firing - but that's an issue to do with the way the firing mechanism and magazine are set up, so it might go off when reloading, or burst-fire when trying to fire single-shot. It's *not* the same as going off when dropped - that's not what "slam-firing" means.

 

[Forbin]

But I suppose if dropping it causes it to go off once by tripping the sear, it could then slam-fire the rest of the mag as it bounces down the stairs...

 

[Trekker4747]

Sort of my thinking, the gun in True Lies simply could have a design flaw, been broken or some other oddity to cause it to fire down the steps. Another aspect of this to test would have been to see if the gun -assuming it would fire as it tumbled down the stairs- would have only fired away from the hero.

 

[Lonemagpie]

But I suppose if dropping it causes it to go off once by tripping the sear, it could then slam-fire the rest of the mag as it bounces down the stairs...

In reality it still wouldn't go off the same way the one in the movie does - it would just burn through the 30-round clip in one very quick burst, not fire anew with each bump on the way down the staircase.

 

[Lonemagpie]

Sort of my thinking, the gun in True Lies simply could have a design flaw, been broken or some other oddity to cause it to fire down the steps. Another aspect of this to test would have been to see if the gun -assuming it would fire as it tumbled down the stairs- would have only fired away from the hero.

It wouldn't - it would have gone through the clip in one burst, regardless of where it was pointing.

Unless it jammed partway, of course, which would still bust the myth!

 

[Forbin]

^True.

 

[Forbin]

My dad had a little .25 auto Vespa slam-fire on him once. It was old and he was trying to fix it, and the new firing pin he installed was too long, He put a full 7-rd mag in, racked the slide, and it emptied itself into the ground. Littlest machine pistol evah!

 

[Christopher]

By the way, I just rewatched the Dollhouse episode "The Attic," which has a flashback/nightmare sequence set during combat in Afghanistan, and it seemed to me, reflecting on last night's MB episode, that they handled the gunfire pretty plausibly -- it was either short bursts of automatic fire with longer pauses between them (for reloading) or single shots fired manually. But then, they were probably basing it on real battle footage, going for realism.

 

[Forbin]

Pretty sure soldiers are advised to keep their weapons in burst mode, or single shot these days. In Nam our guys tended to hose the jungle with mag after mag and hit exactly nothing. The services learned to encourage carefully aimed shots, or short bursts. The M-16/M-4 has a 3-shot burst mode on the selector. One trigger squeeze, 3 shots come out. You have to squeeze again for another 3.

I saw a demo long ago where an instructor hip-hosed a hillside with a half dozen life-sized human targets on it, and hit nothing but the hillside. He clicked over to single shot and fired one shot center-mass on each target in just a few seconds.

Ya know, I'd be interested to see what kind of groups the Mythkids were getting in that test! They never showed us what they were shooting at!

 

[Christopher]

^To clarify, the bursts of automatic fire in the flashback scene were coming from the enemy, not the US soldiers.

But if automatic weapons are so ineffective at hitting things, why make them at all? It seems very wasteful.

 

[Lonemagpie]

^To clarify, the bursts of automatic fire in the flashback scene were coming from the enemy, not the US soldiers.

But if automatic weapons are so ineffective at hitting things, why make them at all? It seems very wasteful.

1) in crossfire they can be deadly

2) One guy with one can make a lot of guys keep their heads down

 

[Trekker4747]

With automatic weapons in combat they're mostly used for suppression. To create a hail of bullets and noise that make it hard if not impossible for the intended target to move lest the risk getting shot. In actual combat situations, like in wars, less than 5% of bullets hit a target the rest is used simply to suppress the enemy to prevent them from shooting and to allow closer-ranged combatants to get into position.

 

[chardman]

The full-auto MAc-10 fires from an open bolt, which makes it vulnerable to slam firing - but that's an issue to do with the way the firing mechanism and magazine are set up, so it might go off when reloading, or burst-fire when trying to fire single-shot. It's *not* the same as going off when dropped - that's not what "slam-firing" means.

In the film, this is precisely what happens, iirc. Jamie lee fires the Mac, panics, and drops weapon, which is still firing as it falls, even before it hits the first step. They even mention the first part of this on Mythbusters, but neglect to note that the gun in the film is already firing before it ever hits the stairs. Which is why I wondered why they were at all concerned with whether a drop impact would cause a gun to fire, as that's not at all what the film depicted.