BB Energy

[Vandetta]

Im not sure if this is a myth but would just like to ask. I heard that the higher weight bb you use the harder it hits, is this true? The only reason I ask is because this equation wouldn't have you thinking so:

Energy = .5 * Mass * Velocity^2

If you notice if you put a 5 in for mass and a 2 in for velocity you have far less energy than if you put a 2 in for mass and a 5 in for velocity.

[swift-silent-deadly]

i cant quite understand your idea, but if you took a gun that shoots 370 fps with .2 g bb, and shot a .25 g. bb the velocity would decrease because it takes more force to move a heavier object. althought the velocity would decrease, the .25 bb would still hit harder than the .2. also the .25 will most likley always be more accurate.

[BLKKROW89]

F=MA

force=mass X acceleration

i have done tests and it is pretty basic physics, no matter what weight of bb you use it will still be the same force because the fact that mass and acceleration or inversely proportional in terms of airsoft.

the smaller the bb the faster it shoots

the bigger the bb the slower it shoots.

the force on the bb upon impact will stay the same no matter what weight of bb you use.

[Whiskey11]

Just a question, has anyone actually gone out and chronoed guns with different bb weights?  From my experience, using .20's in a gun that shoots 430fps then switching to .25's is you see a slight energy creep up using .25's.  I'm not the only one who has seen a similiar creep up when using heavier bb's then .20's.  While I dont have any empirical data with me right now it wont be too hard to obtain!  Get an AEG that chronoes 400 w/ .20's and measure it's velocity with .25's, then hammer out the math.

As for hitting harder, this may relate more to momentum.  Supposedly a .25 bb will have more momentum, but we are talking at the end of the barrel here, once the BB hits the wall of air outside the barrel any form of data is skewed heavily.

[BLKKROW89]

Just a question, has anyone actually gone out and chronoed guns with different bb weights?  From my experience, using .20's in a gun that shoots 430fps then switching to .25's is you see a slight energy creep up using .25's.  I'm not the only one who has seen a similiar creep up when using heavier bb's then .20's.  While I dont have any empirical data with me right now it wont be too hard to obtain!  Get an AEG that chronoes 400 w/ .20's and measure it's velocity with .25's, then hammer out the math.

As for hitting harder, this may relate more to momentum.  Supposedly a .25 bb will have more momentum, but we are talking at the end of the barrel here, once the BB hits the wall of air outside the barrel any form of data is skewed heavily.

momentum  is p=mv or momentum=mass X velocity

and no matter what bb weight you use, if you use a .2 and a .4 in the same gun it will have the same force. But always remember that the velocity of your gun changes basically on each shot because the gearbox is inconsistent.

The momentum of each shot is going to be the same with a .2 or a .25

[Kurn]

But always remember that the velocity of your gun changes basically on each shot because the gearbox is inconsistent.

The BBs may not be all exactly the same diameter or weight too, even very small differences could help to throw the numbers off.

It's not very likely that any airsoft gun is going to break the laws of physics.

[BLKKROW89]

But always remember that the velocity of your gun changes basically on each shot because the gearbox is inconsistent.

The BBs may not be all exactly the same diameter too, even very small differences could throw the numbers off.

It's not very likely that any airsoft gun is going to break the laws of physics.

exactly, the force your gun shoots is what it shoots you cant change it unless you upgrade your gun. Just by using different bb weight doesnt mean your gun shoots harder then with a lower weight

what i want to test is the differences between effective range using the same fps, and different weights and the percentage of change between the various weights. just to find out what bb would be best

[Uchiha Itachi]

.........eh

Object strike each other with the same force. Even though the .2s and .25s are traveling at the same speed/joules the .25s have slightly more mass. Which is why it hurts slightly more since more energy its released on impact and likewise against the BB. Ever wonder why .12s bounce more/higher than .2s?

And the formula is

J=(.5)(kilograms)x(kilometers)^squared

[Whiskey11]

But always remember that the velocity of your gun changes basically on each shot because the gearbox is inconsistent.

The BBs may not be all exactly the same diameter or weight too, even very small differences could help to throw the numbers off.

It's not very likely that any airsoft gun is going to break the laws of physics.

While I would normally agree, airsoft is far from the ideal world that the laws of physics are designed around.  F=M*A is a perfect example of this.  There are far too many factors involved to assume that everything is ideal.  What I'm saying is get off your duff and get me some data rather then throwing about your physics knowledge.  Get measurements before trying to refute another persons point.  

What I'm saying is:  Get some .20's, .23's and .25's in the same brand (go for excel or AE as these are the most common bb's) and measure the FPS with the same chrono and the same gun using the same mag.  Then get out your calculator and calculate the energy levels.

[Ganef]

The laws of physics get us pretty damn far and are not based on an ideal world in any physics text past the 100 level. There is plenty that physical laws say, that airsofters forget when posting on internet sites.

All data is based on assumptions, and there are so many to be made in determining this kind of thing. Not every gearbox behaves the same, and even when you just swap barrels there is a chance that the seal to the air nossle is off enough to disrupt the data. And then who is to say, which is the ideal hopup, bucking, piston head, tight bore barrel, spring, nossle, bb etc...

The way to go about getting range data is to make constant as much as possible and take many data points and extrapolate from that experimental data the results you want based on various curve fitting equations and such. But without a large indoor range, high speed cameras, and many many guns and parts it will be hard to get really exact data, and data that will be of worth to the average airsofter. Not even taking into account the variables that someone trying to maximise their own gun will get right or wrong using our findings.

[Kurn]

--

[BLKKROW89]

But always remember that the velocity of your gun changes basically on each shot because the gearbox is inconsistent.

The BBs may not be all exactly the same diameter or weight too, even very small differences could help to throw the numbers off.

It's not very likely that any airsoft gun is going to break the laws of physics.

While I would normally agree, airsoft is far from the ideal world that the laws of physics are designed around.  F=M*A is a perfect example of this.  There are far too many factors involved to assume that everything is ideal.  What I'm saying is get off your duff and get me some data rather then throwing about your physics knowledge.  Get measurements before trying to refute another persons point.  

What I'm saying is:  Get some .20's, .23's and .25's in the same brand (go for excel or AE as these are the most common bb's) and measure the FPS with the same chrono and the same gun using the same mag.  Then get out your calculator and calculate the energy levels.

first off you you understand any of the basic laws of physics, as in newtons three laws. And yes different bb's have different diameters i was speaking in terms of generalities as in all bb's have a 6mm diameter and if your gun shoots the same speed everyshot.

And yes i have done the math, i actually took the length of my wires inside my gun and figured out the resistance or Ohms of the wiring with deans conenctors, and how many Volts/Amperage Was being used inside my old AK.

i love physics, and i study it a great deal. and im not trying to flaunt my knowledge but help the OP with his question.

i was also thinking of getting a little machine that test's spring constants or (K), and test all the springs out there to put them in their correct order, so we can have a reliable source that if your gun is shooting 380, and you want to get as close to 400 but you drop in a m110 and it shoots 420, then you drop in a m110 and it shoots 385, then you have to find that inbetween.

[Ganef]

I was attempting to that a long time ago. I would be very interested in that kind of graph showing the constants for various springs. I am tired of this m110 pdi170 BS.

[BLKKROW89]

i also wanted to write out a huge all airsoft physics for dummies guide so all the basic answers can be answered, like voltage wattage, fps, everything but idk i got lazy