Most Dangerous BB Type

[The Disavowed]

I was looking at bb weights the other day, and that progressed to me looking at different types of bb, and then I started wondering what would be the worst bb to be shot with, as in what would do the most damage?

 

I saw glass bbs, and also steel bbs, paint bbs, as well as 4.5mm and 8mm bbs. So apart from the obvious depending where it hit you, and I know some are not designed for shooting people with, but it did get me thinking about what would hurt most and what would do the most damage.

 

I was thinking based on a gas pistol, shooting at say 350fps using a 0.2g bb, lightweight vs. Heavyweight vs. Calibre vs. Material, what is most devastating? Can anyone help explain the theories to me?

[NonEx]

And the purpose of this is what?

 

I think there is a rule somewhere on here that you can't/shouldn't discuss how to make an airsoft gun the most "dangerous".

[jal3]

To your body?

Quite simple, it doesn't matter. Your body is softer than whatever you shoot it with.

The more energy it hits you with, the deeper it will go and more it will bruise.

 

The larger it is, the more it will bruise instead of penetrate.

That is why paintball can shoot each other with 12+ joule.

Also why it hurts so much...

 

For optimal range, we should instead be looking at using smaller BB's made of heavier materials. A 4mm steel BB weights about 0,25g, from what i recall, but it will fly so much further than a 6mm 0.25 BB because it is smaller. The difference is huge. Unfortunately, it zips through skin easier as well.

[sandstorm]

I'd say most dangerous is the re-used ones that some idiots pick up and reload their gun with...

[renegadecow]

A 4mm steel BB weights about 0,25g, from what i recall, but it will fly so much further than a 6mm 0.25 BB because it is smaller.

Haven't done the math but a smaller surface area also means less magnus effect.

[The Disavowed]

There is no purpose apart from trying to gain an understanding of why certain things are and what they would do. I am lead to believe that if you use a heavier bb, such as a .4g for instance, then the weight difference from a .2g is obviously double, so it will travel slower down the barrel therefore allowing more pressure to build up behind it, so although lowering the fps because it weighs more, it will have a better flight path and impact harder, therefore hurting more.

 

I saw a stupid argument about glass bbs where someone in China or somewhere fired hundreds of glass bbs from an aeg into a car window at close range until it broke, and then proceeded to say how bad glass bbs are and how dangerous aegs are. Stupid argument in my opinion, anything can be made to look worse than it is, but I figure that they must have a purpose.

 

Obviously if you were to shoot someone wearing mesh goggles with a paint bb it would not be nice, but the reason for them is obvious, and hopefully nobody would be stupid enough to misuse them, but how dangerous would they be if they were to say hit you on the forehead at 20 yards?

 

Also what adverse affect would they have on your gun? BB guns are not paintball markers, so would they ruin your gun??

 

Like I said, I am trying to gain a better understanding of how what and why really.

[renegadecow]

You're describing Joule creep with the example between bb weights. As far as mass is concerned directly, the more mass an object has, the longer it can retain its momentum. So a heavier projectile will have more potential harm at range vs a lighter one.

Paintball are meant to disintegrate on impact. A shot to the forehead will hurt, but won't be seriously harmful unless the rigidity of the projectile is changed. As for using them on airsoft, it's largely useless due to technologies that can break the paintball prematurely like hop up and spring loaded mags.

[Guges Mk3]

Are you currently in school?

 

If you are...this would be a good time to have a Physics class.

[Mike 8-{>]

I have to admit I don't see the point of the question. Kinetic Energy KE = 1/2mv^2  or 0.5mv^2  where m = the mass of the projectile (BB)  and v = velocity.  Whatever BB you fire it obeys the physics. Heavier BBs will carry more kinetic energy. However the velocity is squared so increasing the muzzle velocity has a bigger impact on KE than increasing than mass of the BB. It increases with the square of the velocity increase.

Initial calc

0.2g, 100ms

KE = 1/2mv^2 = 0.5 x 0.0002 x 100^2 = 1J

 

0.4g, 100ms

KE = 1/2mv^2 = 0.5 x 0.0004 x 100^2 = 2J

 

0.8g, 100ms

KE = 1/2mv^2 = 0.5 x 0.0008 x 100^2 = 4J

 

Initial but double velocity

0.2g, 200ms

KE = 1/2mv^2 = 0.5 x 0.0002 x 200^2 = 4J

 

0.4g, 200ms

KE = 1/2mv^2 = 0.5 x 0.0004 x 200^2 = 8J

 

0.8g, 200ms

KE = 1/2mv^2 = 0.5 x 0.0008 x 200^2 = 16J

 

Initial but quadruple velocity

0.2g, 400ms

KE = 1/2mv^2 = 0.5 x 0.0002 x 400^2 = 16J

 

0.4g, 400ms

KE = 1/2mv^2 = 0.5 x 0.0004 x 400^2 = 32J

 

0.8g, 400ms

KE = 1/2mv^2 = 0.5 x 0.0008 x 400^2 = 64J

 

 

Unless you go above legal muzzle energy limits then it is down to the KE the BB carries to the target and how much is lost to drag on the way. When it gets there it is the surface area of the projectile that matters as the energy on impact transfered to the target is distributed over the surface area of the projectile.  Assuming cross sectional area (for simplicity rather than getting into handling the BB being a sphere and the impact area changing with time as the BB strikes the target.)
 

8mm dia = pi r ^2 = pi x 0.004 ^2 = 5.026 e-5 m^2 = 50.26 mm^2

 

6mm dia = pi x 0.003 ^2 = 2.827 e-5 m^2 = 28.27 mm^2

 

4.5mm dia = pi x 0.00225 ^2 = 1.590 e-5 m^2 = 15.90 mm^2

 

2.5 Joules KE per sq mm KE/Area = J per sq mm = J/mm^2 (so a 0.2g BB, same mass for each diameter)

8mm BB KE per sq mm 2.5/50.26 = 0.050 J/mm^2

6mm BB KE per sq mm 2.5/28.27 = 0.088 J/mm^2

4.5mm KE per sq mm 2.5/15.9 = 0.157 J/mm^2  (less than half the dia of an 8mm BB but more than 3 times the energy per sq mm)

Theoretical 1mm dia BB KE per sq mm 2.5/1 = 2.5 J/mm^2

 

So bigger area projectile = less energy per square millimeter. (again a square thing but this time an inverse square)

1/1 =1

1/2 = 0.5

1/3 = 0.333

1/4 = 0.25

1/ 5= 0.2

Inverse square

1/1^2 = 1/1 = 1

1/2^2 = 1/4 = 0.25

1/3^2 = 1/9 = 0.111

1/4^2 = 1/16 = 0.0625

1/5^2 = 1/25 = 0.04

 

 

For comparison:

 

5.56mm bullet ( figures from https://www.quora.com/Which-has-higher-penetration-power-a-5-56-rifle-round-or-a-12-gauge-slug)

Mass= 0.00356394 kilograms = 3.56g

Diameter = 5.56mm

Velocity = 993 m/s

Ke=1757.1097365 J

 

5.56mm area = 5.56/2 = 2.78mm = pi x 0.00278 ^2 = 2.4279 e-5 m^2= 24.279 mm^2

 

5.56mm KE per sq mm = 1757.1097365/24.279 = 72 J/mm^2

 

 

0.22 Air gun at UK legal max Muzzle energy 16J = ~ 12 ft/lbs

KE max = ~ 16 J

Dia = 5.5mm

Area = pi x 0.00275 ^2 = 2.376 e-5 = 23.76 mm^2

5.5mm KE per sq mm = 16/23.76 = 0.6734 J/mm^2

 

As to BB material it really doesn't matter unless the projectile is frangible (as mentioned by RC above) and disintegrates on impact which would dissipate more energy so less "damage". Otherwise all BBs can, I think, essentially be described as solid / non deforming so will transfer all their energy to the target on impact. For an airsoft rifle shooting a person, at UK legal muzzle energy levels you aren't getting to the energy ranges which would cause a BB to disintegrate, unless it is a paint BB and is designed to, as people a squishy and covered in deformable fabric (more energy absorbing/dissipating) for the most part. So really the damage question doesn't go beyond a heavier BB carrying more KE than a lighter one.

 

I don't think it is appropriate to speculate on what you could achieve with a BB gun as we aren't in it to do damage to each other. 

[The Disavowed]

Thank you for a very detailed and informative reply, that really goes a long way to answering my thoughts. I never wanted to imply that I want to hurt someone, far from it, if I wanted to do that then just use a real gun! No, I just really want to understand more about why different things are, I mean, there must be a genuine reason for using one type of ammo over another.

 

I still don't understand the purpose of glass bbs though? Why glass?

[renegadecow]

It's very hard stuff. Punches through cans and whatnot much easier for people who only like to do target practice with their airsoft guns.

[The Disavowed]

Ok, so what about steel? Surely that is harder, or is it more expensive??

[renegadecow]

You can get steel bbs too. But they are too heavy to provide any appreciable hop up.

[Guges Mk3]

Not to mention steel bbs will eat the softer alloy inner barrels.

[The Disavowed]

Thanks, I really feel that I have a better understanding of all of that now. And once again, the purpose is not to inflict damage upon a person however much of an evil grin comes across my face when I hear a call of "ow! *fruitcage*! Hit!!" (And I know I'm not the only one ;-) ) but merely to satisfy a question that just popped into my head.

[Lone_Bullet]

I used Bioval BBBMAX clear .27's at the start of my airsoft timeline.

Very good stuff! 

 

Until they noticed at Berget that it'll embed itself in a car's windshield at only 350 FPS. Can't remember the distance.

They were 'Bio' bbs, but they actually looked like glass with the only thing damaging the BBS was shooting 2 at each other ( like in a barrel blockage ) or brute crushing force with a hammer.

 

I loved them, but threw them all in the bin after I got word. They were banned in a lot of organisations afterwards.

Truth me told, if it wasn't for the internet, we were probably all still plinking away with these BBs.

 

The thought...

 

sadface 

[Guges Mk3]

I used Bioval BBBMAX clear .27's at the start of my airsoft timeline.

Very good stuff! 

 

Until they noticed at Berget that it'll embed itself in a car's windshield at only 350 FPS. Can't remember the distance.

They were 'Bio' bbs, but they actually looked like glass with the only thing damaging the BBS was shooting 2 at each other ( like in a barrel blockage ) or brute crushing force with a hammer.

 

I loved them, but threw them all in the bin after I god word. They were banned in a lot of organisations afterwards.

 

sadface 

BIOVAL .27 was actually silica glass, which is essentially "sand".  So that is why it is called BIO.  There was a slow motion video back 10+ years ago of regular plastic bbs hitting a windshield and the Silica BIO-Val's.  The Plastic bbs actually deformed on impact.  The BIOval-Silica...did not.

[icolater]

Yea or even just using the gun as a club LOL

[3vi1-D4n]

Thank you for a very detailed and informative reply, that really goes a long way to answering my thoughts. I never wanted to imply that I want to hurt someone, far from it, if I wanted to do that then just use a real gun! No, I just really want to understand more about why different things are, I mean, there must be a genuine reason for using one type of ammo over another.

 

I still don't understand the purpose of glass bbs though? Why glass?

 

Its simple really, why we use heavier vs lighter ammo.

 

1) The heavier the round, the slower the deceleration due to air resistance (drag), it maintains the impact energy for longer distance.

2) The heavier the round, the less effect wind would have on the projectile.

3) The heavier the round, the less effect foliage has as a barrier to penetration.

 

 

It means the heavier the BB, it will hurt more at longer distances and would be easier to predict its flight path (rather than slowing down quickly) hence more applicable to long range engagements.  However, lighter BBs reach point A Faster in shorter range engagements. 

 

Preferences for hardness is useful if you want the impact to transfer more forces in a shorter amount of time, over a smaller surface area.   Difference between aluminium BBs vs plastic BBs on skin would be less dramatic than it would on a surface that is harder (say glass). 

 

A 0.25g Plastic BB will deform or break apart on impact to glass, but a aluminium BB will break glass, even though they are shot from the same gun on the same impact energy.  On bone, that may become dangerous if the hardened BBs are travelling fast enough.  However the impact felt on skin/muscle would be the same.

 

 

So simply:

 

1) CQB 0-100ft (0-30m), you want less accuracy, negligible for wind effects, but quicker reach, then use light BBs, i.e 0.2g

2) FIBUA 0-200ft (0-60m), you want some accuracy, though with some wind effects, but a balance of suppression and quick reach, then use a moderately powered gun with medium weight BBs, i.e. 0.25g-0.28g

3) Machine gun 0-250ft (0-75m), you want some accuracy, a lot of wind effects, but want to ensure you keep heads down for quick reach, then use a high powered gun, with medium weight BBs, 0.25g-0.28g.

4) Precision rifle 0-250ft+ (0-75m+), you want accuracy and consistency, lots of wind effects, use a high power gun with heavy BBs. i.e. 0.36g-0.42g

5) Jungle/close country 0-150ft (0-50m), you want less accuracy but more bush penetration, use a medium power gun with heavier BBs 0.28g-0.36g

 

 

Technical reference:

 

https://en.wikipedia.org/wiki/Drag_equation

https://www.grc.nasa.gov/www/k-12/airplane/Images/exthrst.gif

[Gunnman]

Anyone one using an airsoft gun as a self-defence weapon is asking for trouble. Especially, after the perpetrator figures out that your gun is a toy and his knife/club/gun is real.

[The Disavowed]

Airsoft guns are definitely not designed for self defence purposes. Rubber paintball sized compliance rounds however...but not airsoft, and not the point of my original question.

[icolater]

Yea I have a shotgun for that purpose.

[The Disavowed]

Beanbag??

[icolater]

Yep, would KO someone cold if needs be. But TBH I wouldn't use though just incase. I've been boxing for years so I would be confident enough just to use my fisty cuffs.

[AG1212]

Yeah using airsoft for self defense is just silly, unless you have pests on your land you want to chase off without resorting to lethal means. 

 

Having said that, something like the APS CAM870 can show you how dangerous joule creep is. With 12 .2s it each BB will hit at around 280 fps, doesn't really hurt at 5+ meters. But when I plinked with .3s the range more than doubled but the energy they had was insane, probably more than 400 fps at a guess. Depending on your set up, heavier bbs will result in less energy wasted from the propellant, more transfer to the BB.

 

What's even scarier is using rubber paintballs in the CAM870, not that I would because that's illegal here...but that would be the closest to a self-defense airsoft gun I could think of, especially if you charged the shells with HPA.