Placeholder Image

Subtitles section Play video

  • - A quick caveat before we get started here,

  • I do not want Smarter Every Day to be observed as

  • a channel that glorifies weaponry.

  • I am just fascinated by fluid dynamics,

  • ballistics, optics,

  • mechanics, aerodynamics.

  • All this stuff is just fascinating to me.

  • And I am hard-pressed to find one singular thing

  • that I can study that wraps all these physical phenomenon

  • into the perfect Venn diagram that tickles my brain

  • quite like firearms.

  • So, that's why you'll see me studying firearms so often

  • and I hope you realize that I'm doing it as intelligently

  • and respectfully as I can.

  • That being said, I've made some observations

  • in the last episode and I've learned some stuff.

  • And I've also decided to push it a little further

  • by studying suppressors.

  • So, let's look at this and try to get smarter everyday.

  • First, let's revisit what we learned in the last episode.

  • Using a phantom camera with a clever photography technique

  • called Schlieren, which is German for streak by the way,

  • we observe that the supersonic bullet creates

  • an angular shot cone and the angle of that cone can

  • be used to determine the mach number.

  • We also learned from Dr. Konigstrasse at UAH

  • that a bullet travelling in the transonic regime

  • can create supersonic flow around it

  • because the air has to speed up

  • and rush around the outside of the surface of the bullet.

  • This is a connection I didn't make at the time

  • but we've all see these awesome pictures

  • of a fighter jet with this cone of vapor behind it,

  • this is totally why that happens.

  • The jet is flying along in the transonic regime

  • just like that bullet and just like the normal shockwave

  • that occurs on the side of the subsonic bullet

  • that's happening on the jet.

  • And it does two things, number one,

  • it makes this cone of vapor form on the jet

  • and number two, it makes me all tingly inside.

  • Okay, so I think we have a good understanding

  • at this point of shockwaves created by a bullet itself.

  • You may have heard someone talk about the crack of a bullet

  • as it passes, that's created by this shockwave.

  • But if you think about the bang of a gunshot,

  • it's all those rapidly expanding gases

  • out the front of a muzzle right?

  • So it's time to hone in on that area right there

  • and study that with super schlom,

  • super slowmo suppressor Schlieren, there you go.

  • It's hard to say.

  • In a past episode of Smarter Every day

  • I asked a company to fabricate a see-through suppressor

  • so we could see the flame front propagate

  • through the baffles and try to understand what was going on.

  • That was effective in showing what happens on the inside

  • of their particular suppressor design

  • but what I wanna see is exactly what happens

  • on the outside of the suppressor,

  • after all, that's where all the noise is.

  • Here's my friend Coop firing his rifle

  • chambered in 300 blackout, both suppressed and unsuppressed.

  • I want to show you a full minute of slow motion video

  • because I believe it does the best job of explaining

  • the physics of what's going on.

  • On the left we have a suppressed weapon

  • and on the right we have the same weapon unsuppressed.

  • When they're first fired you can see straight away

  • that the weapon on the right seems to have a larger,

  • dirtier blast but after four milliseconds

  • there doesn't seem to be any more shockwaves,

  • we're just venting the exhaust gases at that point.

  • The weapon on the left, however, is still chugging away.

  • It's like this initial blast is bouncing around

  • on the inside of the suppressor

  • and just a little bit of the gases

  • are being leaked out with every reverberation.

  • (gunshot echo)

  • Watch what happens next though.

  • On the right, the echo from the unsuppressed weapon

  • is huge and very distinct.

  • You can see how powerful and singular

  • that initial blast was

  • by how sharp the echo is when it returns.

  • Imagine that echo entering your ears,

  • meanwhile you can still see that the suppressed weapon

  • is dissipating that acoustic energy slowly.

  • This is like the clearest example I can show

  • of that energy being dissipated differently.

  • On the right, the unsuppressed version,

  • the whole thing's over in a millisecond and a half

  • but on the left, the same acoustic energy

  • is dissipated over 15 milliseconds.

  • That is a direct comparison showing you

  • that it almost acts like a capacitor in a circuit,

  • it's like, slowly filtering the energy as it exits.

  • Anyway, that energy dissipation does not come for free.

  • Suppressors heat up very, very quickly.

  • All that thermal energy is captured

  • because it doesn't dissipate away from the weapons.

  • So the problem with suppressors is

  • if you fire enough rounds through 'em,

  • they heat up very, very fast and they can cause malfunctions

  • and even damage to the weapon.

  • Now let's look at subsonic ammunition

  • being fired from a suppressor.

  • This is absolutely fascinating.

  • Okay first observation.

  • The first thing that leaves the suppressor is unburnt powder

  • and look at that, there's little baby shockwave,

  • they're supersonic.

  • Now whether this is gunk coming loose

  • from previous shots, or whatever, I don't know

  • but it's clearly supersonic.

  • Second, did you see that little vortex ring

  • poot out the end?

  • Okay, here we go, bullet time.

  • We know this is a subsonic round

  • so we're expecting normal shockwaves

  • on the sides of the bullet but look at that.

  • They're not there until the bullet

  • is several inches away from the muzzle.

  • It is crazy to think about how complicated

  • this flow environment is but it's really fun

  • to make these observations and try to figure it out.

  • This episode of Smarter Every Day is sponsored

  • by Hello Fresh.

  • Hello Fresh is a meal kit delivery service

  • that sends ingredients to your house in a bag

  • and you get a little instruction thing

  • and you go through and you get to make food

  • at your house that you wouldn't normally cook.

  • It's a subscription service, we can pause it

  • if we go out of town.

  • It really works for us.

  • Is that, what are you doin' right now?

  • Does it say use your hands?

  • - No it didn't, it just says to mix.

  • - Have you ever eaten a jalapeno?

  • - No.

  • - Today's the day buddy.

  • - Mummy's gonna have her burger without jalapenos (laughs)

  • - You can't deviate from the recipe.

  • - Yeah, yes I can

  • (laughter)

  • - Hello Fresh is America's number one meal kit service

  • and right now it's coming in at about 6.99 a serving

  • which is really, really affordable

  • so you get to try new food

  • you get the stuff sent to your house

  • so you don't have to worry about shopping.

  • That's your favorite part, right?

  • - Absolutely!

  • - You don't have to like...

  • - I don't have to shop.

  • - (laughs) Awesome.

  • Get started with six meals free

  • by going to HelloFresh.com and using the promo code

  • smarter60 for a total of 60 dollars off.

  • That's two free meals in each of your first three boxes.

  • Big thanks to Hello Fresh for sponsoring Smarter Every Day

  • and for making this happen.

  • I really like it when this happens

  • and yeah, give it a shot.

  • I think you'll dig it with your family, it works for us.

  • What are these little squirrely things

  • that come out of the suppressor?

  • - Okay, so what you're seeing here

  • on this blackout cartridge is your seeing unburnt

  • propellant leaving the muzzle before the bullet goes

  • and so for 300 blackout optimally you get complete

  • burnout around 9 1/2 to ten inches of barrel length.

  • So this is a 10.2 inch barrel length

  • so we're right on the threshold of burning