fps table?

[shadowhunter]

could someone point me in the right direction of one of those funky
FPS-->BB Weight
tables please?
ive seen loads on the forum but cant find any?
thanks,

oh yeah, mods, this will be closed when i get an answer.

[Could Not Think Of A Name]

Re: fps table???

It doesnt go by BB weight, it goes by power of spring.

[shadowhunter]

Re: fps table???

oh, well one of those funky tables nonetheless

[Caveira]

Re: fps table???

It doesnt go by BB weight, it goes by power of spring.

For any given power of spring, the fps changes with the weight of the BB.

E=Mc2:p

[Could Not Think Of A Name]

Re: fps table???

For any given power of spring, the fps changes with the weight of the BB.

E=Mc2:p

Yes by like 0.something

Hes meaning bigger changes.

[Bezza806]

Re: fps table?

they say you lose about 40fps for every .05 increase in bb weight over a .2

[Could Not Think Of A Name]

Re: fps table?

they say you lose about 40fps for every .05 increase in bb weight over a .2

Thats if your using the same spring, the OP is looking for a spring guide. So higher spring = Higher FPS.

[Caveira]

Re: fps table???

Yes by like 0.something

Hes meaning bigger changes.

No, by dozens of fps. If you increase from a 0.20 to a 0.25, you have increased the mass that the air displaced by the spring needs to move by 25%. That reduces the fps considerably.

To give you an example, I just chrono'd my pistol with 0.20 and 0.25 BBs, at 255fps and 228fps respectively. A reduction of 11%/

Please don't post if you don't know what the hell you're talking about.

EDIT: Where does the OP ask for a spring guide? He only mentions fps and weight.

[Scarface73]

Re: fps table?

Try this and make your own table in excel.

Link Removed

For all those that don't understand the interaction between mass and energy. There is a reason people set fps at 328 for a 0.2bb, it's exactly 1 joule. Add a 5% tolerance and you start approaching the legal limit of 1.35 joules.

Thats why putting a 0.3bb to get your rif under a 328 chrono limit makes you a $£%&$£%"£^"£$*"£%$££$ head!

So how many of you who fail a maths 101 have illegal weapons lol.

[starscream]

Re: fps table?

So how many of you who fail a maths 101 have illegal weapons lol.

I would imagine a fair few. And from the rumours I've heard, the police are having a bit of a crack down on ALL guns over the 1 joule, (+5%) limit. Including single fire, and bolt action.

[TS_Welshy]

Re: fps table???

For any given power of spring, the fps changes with the weight of the BB.

E=Mc2:p

is it not E=1/2mv2?

lol

[Bezza806]

Re: fps table?

Thats if your using the same spring, the OP is looking for a spring guide. So higher spring = Higher FPS.

no he isn't he is talking about the relationship between fps and bb weight.

[jagillham]

Re: fps table?

For you sir.....

Assuming a normal AEG, the only springs you'll really use will be M90, M100, M105.

The only BB's you'll probably use will be .20g, .23g & .25g

All power ratings are measured using a .20g BB. You cannot exceed 328fps (+/- 5%) legally.

A M100 spring with a .20g pellet will show a reading of around 330fps. With a M105 around 350fps, and a M90 around 300.

As per above, to keep it legal (and you out of jail!) the strongest spring to try in a automatic airsoft weapon is the M105. This spring with a .25g BB will give around 320fps.

Higher rated the spring the higher the fps shown. The heavier the BB, the lower fps shown. If you use heavier ammo to hide the true spring power, this is very dangerous. 350fps is not much higher than a real shotgun velocity, but the weight of the projectile (at that speed) is what makes the danger.

Consider throwing a ping pong ball hard as you can at somebody, then do the same with a golf ball. Both are thrown at the same speed, but one is much more dangerous!

[Bezza806]

Re: fps table?

350fps is not much higher than a real shotgun velocity

not sure where you found that out as a standard 12 gauge muzzle velocity is around 1100 fps

[kipper66]

Re: fps table?

Consider throwing a ping pong ball hard as you can at somebody, then do the same with a golf ball. Both are thrown at the same speed, but one is much more dangerous!

thats probably the best way i've heard it put!