Episode 51: Myths Reopened
- You can fire a bullet from a rifle or handgun underwater: confirmed. A 9mm or .357 magnum would be lethal at 2ft.
- salamis as rocket fuel: confirmed
- splitting an arrow from nock to tip: still busted
Update: salami rocket revisited in More Myths Revisited
Splitting an Arrow
Fans complained about the arrows and the bow used in the original mythbusting. Given that this was a Robin Hood myth, they revisited this myth using medieval-accurate bows and arrows. One of the fans was kind enough to send in hand-picked pieces of straight grain cedar from British Columbia. They also changed to long bow instead of a compound bow.
The components of the new setup were:
- medieval arrow:
- hand-split straight-grain timber (cedar)
- goose-feather fletchings
- hand-forged field tip arrowhead
- goat-horn-tip nock (may actually hinder the splitting attempt because it is harder)
- rebuilt arrow-firing robot (original was chopped up last time to make room in the shop)
- long bow
Their initial firing didn't go so well -- their medieval arrow didn't fly very straight. They decided to go with point-blank firing instead -- the tip was lined up to nock and fired. That didn't go so well. When they fired a medieval arrow at a medieval arrow, the arrow that was fired snapped in half when it hit the nock of the target arrow. The modern arrow they fired point-blank at the target arrow also snapped in half.
They decided their point-blank test was pushing the arrows too much, so they took their arrows out to the firing range. To solve the problem of the arrows not firing straight, they fired modern arrows at their medieval-accurate arrows targets.
As it was in the original mythbusting, they hit the target arrow multiple times, but the fired arrow deflected to the side. The difficulty in splitting arrows is partly because arrows don't actually fire straight -- they wobble through the air.
They brought in a professional shooter, Jim Long, firing carbon fiber arrows. His first shoot split a little bit off the side of the target arrow. Many of next shots hit and deflected off the nock. After 60+ arrows, Jim was able to split the target arrow 10" down (about a third of the way down). They looked at the evidence and decided that Jim's shot was as good as a shot could be -- dead on, but still not enough for nock to tip.
Replicating the myth
They think that hollow, possibly bamboo, arrows were used in the Errol Flynn Robin Hood movie shot. To replicate how a nock-to-tip shot could be done, they replaced their target arrow with a bamboo arrow. Jim Long's first shot split the bamboo arrow from nock to tip.
Confederate Rocket/Salami Rocket
Update: the MythBusters did a revisit of this revisit -- Salami Rocket Revisited
They actually did the original myth knowing that they would revisit it. They wanted to test the myth using salamis as fuel, but just didn't have time the first time around.
Jamie: "This may look like a salami, it may smell like a salami, it may even taste like a salami, but it's rocket fuel."
The original rocket consisted of a liquid nitrous oxide half and a paraffin wax half. The new salami rocket replaced the paraffin wax with a tube of salamis. The center of the salamis was drilled out and filled with black powder.
They modernized the technology used in the rocket this time around:
- A better launch system: fill shutoff, quick-release removal of filling hose, and launch button.
- Improved liquid nitrous oxide filling system: use a vacuum to suck the nitrous oxide in (they abandoned this later and went back to the old manual filling)
Alameda test launch
In the first Confederate Rocket episode, they test fired their rocket indoors and ended up lighting the inside of their shop on fire. This time around, they took their rocket outdoors to Alameda to test the salami rocket engine The rocket was locked down so that it wouldn't actually launch into the air.
Adam: "This is another one those things where you just run through so many of the safety procedures and so many of the systems in your head, that every now and then you have to remind yourself and go, damn! I'm writing salamis, man, I'm making a rocket out of meat!"
And the test firing:
Adam: "What was that"
Jamie: "The rocket is gone"
Adam: "No way"
Adam: "Did it blow up?"
Jamie: "Yeah. The engine is gone."
The salami fuel was too strong and blew up the rocket."Carnage asada" - Adam.
Desert launch with new salami rocket design
They decided to shrink things down to two paintball tanks -- one with salami, one with liquid nitrous oxide. Smaller, and hopefully less explosive. Their rocket expert Robert Gates (JATO car, 360 swing set) also replaced the black powder they had been using with modern hobby rocket fuel. The hobby rocket fuel gives a 3-4 seconds steady burn versus the quick flash of the black powder.
- 20% of blowing up right on the stand
- 50% <20/30 ft
- Rest: a couple thousand feet
The launch was rather limp: the rocket flew up about 20 ft, faltered, and went sideways and fell.
Adam: "20 ft man, what did I tell you!"
Launch 2, with camera footage
Robert Gates hooked them up with an onboard camera so that they could get better footage from their flight. The nozzle blew out of the rocket, so the rocket barely launched. The camera also blew out, so no footage.
Jamie: "Hey a flight's a flight, we got airborne, so it's confirmed"
Adam: "I'm gonna stick with paraffin."
Bullets Fired Into Water
This time around, they want to test if it was possible to fire ordinary guns underwater. There were to questions in particular they wanted to answer:
- Will an regular gun fire underwater?
- At what distance is would a bullet (from a regular gun) fired underwater be lethal?
- Water trough that the bullets were fired through
- Movable ballistics gel target to test lethality
- Colt King Cobra, .357 magnum full metal jacket
- Sig Sauer P239, 9mm
- M1 Garand/.30-06
- 12-gauge shotgun
Tory made sure that there was no air in the barrel because, if there was, the barrel could explode.
The first up was the 9mm. Without a ballistics gel target, the bullet went 18 ft. This answered the first question: yes, you can fire a regular gun underwater (confirmed). The 9mm bullet was intact, but the casing wasn't ejected from the gun. Instead, it was stuck in the slide, so you would only get one shot underwater.
Now they had verified that you can fire a gun underwater, they moved onto testing lethality. In the original episode, they found that a 9mm gun fired into water was lethal at 8ft. No so for a bullet fired underwater: the 9mm bullet didn't even come close to penetrating the target at 10ft. They next moved the target to 2ft, at which point they couldn't find the bullet. Same with the .357 magnum: they lost the bullet when fired at 2ft from the target.
Back at the shop they dissected the ballistics gel block and found the 9mm at 4" deep and the .357 magnum at 5.5", i.e. both would be lethal at 2ft.
The other guns didn't fare as well. The 12-gauge shotgun cracked on firing with heavy damage to the barrel and stock. The impressive M1 Garand also fared poorly. The M1 has an exit velocity of 2700 ft/s, 3 times the energy of the other guns they were testing, but in the original Bulletproof Water episode, they had already seen it fail to shoot into water -- bullet shattered on impact. The firing underwater was equally unimpressive: the bullet was intact, but it only went 6 ft, less distance that the 9mm.
You can fire a bullet from a rifle or handgun underwater: confirmed (you can't use a shotgun underwater). However, it is more lethal to fire into water than it is to fire underwater.