Are guns slightly over 350 fps allowed?

[Joker]

Just going to point this out that you can use heavier BBs when you're slinging plastic if you have a higher FPS I believe...

[bubba]

That lowers the fps but the joules are the same as shooting the gun with lighter bb's.

It may chrono lower but the gun would still be doing more damage and making injury more possible.
A gun shooting 340 fps with .40 bb's, that's about 2 joules.
A gun shooting 340 fps with .20 bb's, that's about 1 joule.

[Joker]

I see, but I was just pointing something out to help him figure out his FPS issue. Hope that makes sense.

[Rios]

And you have to use .20 at the chrono anyway. I dont think above 360 should be allowed almost ever unless you have a special case.

[Joker]

I know that too. I was just telling him how to "lower" his FPS.

[bubba]

It's still dangerous to be using a gun that shoots to high. If the gun shoots to high and you put heavier bb's to make it seem like it shoots right is just dangerous.

A spring change is pretty much the only way to change the fps of a gun if it's shooting high.

[Joker]

Thanks for pointing that out. I know the way I said it made me sound like a total noob, but I was just telling him (probably) the cheapest way... Definitely not the best way. Nor the safest. I think it would be a good idea to shoot it off a couple of times and let the spring "soften" up a bit and if it's still shooting high, then invest in a weaker spring.

[Sleepy]

Using heavy bbs does nothing at all.... It does the same damage as a lighter bb at higher speed. I hope that is clear....

[Joker]

I know what you all are saying. He wasn't particularly asking about the damage, he was asking about FPS. My response dealt with FPS, not about damage.

[Grifter]

The Speed limits are in place to limit the force of impact of a BB.

The Airhouse has a limit of 350 fps with .20 bb because that is what they have deemed a safe amount of impact or hit force ie.. Joule

A .25 bb traveling at 320 fps has the roughly the same force or Joule as the .20bb at 350 FPS so even though a .25BB is "slower" FPS its the same impact.

So if the gun shoots at 370fps with a .20BB and you change to a .25BB and chrono at 340 FPS the gun is still considered "hot" due to the force of impact the BB will have.

The best method to slow your FPS with a hot gun would be a spring change to a less stiff spring.

A spring will lose some of its stiffness over a period of use and that will also cause some loss of FPS which is known as a break or bed in period.
Loony and Raptor both gave examples of a gun that once bedded in was within the limit for the Airhouse.

My Raider shoots at 345FPS with .20's and at 290-295 FPS with .25's atm.

[Joker]

I'm no longer going to try to say what I was before as it seems it's been noted as invalid.
Not too off topic I hope, but do chronos measure joules too?

[Grifter]

I am unsure but I do not thinks so. I know that the ones at the Airhouse will measure FPS and the RPS(Rounds Per Second).

There is a very long and complicated set of math equations to figure out Joules.
Here is an excerpt from an article about FPS, BB weights and Joules.
The article can be found here- www.airtacdepot.com/content/Airsoft_Guns-_How_FPS-_Joules_and_BB_Weight_Effect_Accuracy.htm

Joules:
Joules is another way to calculate the power of your gun. A Joule is a measurement of energy and is stored in every BB. Different weights of BB's can also hold a certain amount of energy even though they are made of plastic or biodegradable ingredients and are the same size as its lighter or heavier counterparts.

You will normally not see Joules as a form of measuring power on many website because it is much more complex and uses a mathematical equation to find out the amount stored in each BB. Unlike FPS, Joules will stay at a constant in conditions with harsh winds and days with clear sky and no breeze.

To find out your Joules, you will first need to turn your Feet per Second into Meter Per Second using the mathematical equation.

M=F x 0.3048
M= Meters
F= Feet

Then turn your Grams into Kilograms using this equation.

Kg=.001 x G
G= Grams
Kg= Kilograms

The Equation that is used now for you to get the amount of Joules in each shot is this.

E=½ x M x V^2
E= Joules
M= mass in kilograms
V= velocity in meters per second

We will use 270 FPS and .20g BB in this example equation:

275 x .3048 = 83.82 Meters per Second
.001 x .20 = .0002 Kilograms
½ x .0002 x 83.82^2 = 0.702579

So in a .20 gram BB going at 275 FPS carries 0.702579 Joules of energy in each shot.

By measuring your airsoft guns power in Joules you can get a better feel for how accurate and powerful your gun is. An airsoft gun that shoots at 380 FPS with 3J hits much harder than one that shoots 380 FPS with 1J, so please take safety into account. Use a trial by fire method, would you want to be shot by your own gun? If you wouldn't like it, I doubt your friends or other players would like it as well.

Now that I have confused you enough let me sum up what just happened. The FPS effect’s your Joules which are affected by the weight of your BB. So the heavier the BB the more energy in the BB giving it more force so it can travel longer and straighter (and it will hurt more!)

[Joker]

No actually that made complete sense. Thanks for the pointer!

[Brush]

May 21, 2013 21:19:21 GMT -5 Joker said:

Not too off topic I hope, but do chronos measure joules too?

Yes, at least mine does.

[Simon]

The chronos at the airhouse do indeed measure Joules.