Joule chart

Share on facebook
Share on twitter

Joule Creep explained and demonstrated - Tech Tuesday - Airsofty SCIENCE!

5 734 views | 3 Mar. 2015

In simple terms, joule

In simple terms, joule creep causes your gun to fire with more force when you load heavier ammo. No other changes are necessary.

So it's important to be aware of it, as if you chrono safe for your field on one weight, and then switch to a heavier one to play, you could put yourself over your field limit by a pretty substantial amount and cause someone serious harm.

Airsoft is a game based on skill and honesty, it's not about causing people pain, so make sure you obey your field/site's power restrictions.

Find me on Facebook @


Twangarang 82

great vid, i use an aeg but its good to know more about the sport


very nicely explained

Vasriotaep - French GBBR Airsoft Player

Thank you! Now they will not say I'm a liar!!


So, sorry if I missed this in the video but, what would be the best way to combat this issue? I know you mentioned reducing the inner barrel length but are there any other ways, and if not how might I find how short I should cut the inner barrel or would I have to resort to guess and check working my way down?
Edit: Specifically for a gas gun I mean.


Is there a 1J limit in the uk like in ireland aswell?

Snakenator WZ

So going off what you said, I would assume that if you had a standard bore in your gas rifle (say 6.06) then joule creep won't cause as much of a significant increase to the rifles muzzle energy because the wider bore means more of the gas can escape past the BB. Therefore the gas will have less time to accelerate a heavier BB as it can simply pass it, granted joule creep will still be there regardless but won't be as dangerous.

Also here's a thought though, would joule creep also affect HPA guns as they use a similar form of propellant?
Video was super useful btw, I'm getting a WE L85 in a few days and I can now use this knowledge to educate others.


Nice video,when will you put up more gameplay?


I'm really struggling to decide between this and the ICS L85A2, any suggestions?

nicholay osokin

I don't understand why .1 is such a big deal. I barely feel the difference. People at fields need to chill. I don't own hpa but I don't see a problem with it


370 fps will not imbed a bb into someone's skin....i shot myself point blank with my pistol shooting 350 to make fun of someone crying about being overshot by someone else and it broke the skin that was it, from maybe 6 inches away.


you had any experience with wide bores, as ive had my eye on one of those orga barrel sfor me we m4, wondering if they would be any good, also what bb weight would you reomend for a wide bore

Lully Lew

Super informative, thanks!

Joule chart

Share on facebook
Share on twitter

Explaining Joule Creep in Airsoft

12 959 views | 7 Aug. 2017

Garrett brings out the

Garrett brings out the white board once again to demonstrate the phenomenon that is Joule Creep!


Excellent Explanation. I sent the link to this video to several people I know and even posted it on my Facebook page. I think more fields need to start using Joules to chrono.

Mr. Google87

So if my scorpion evo can lift the 0.46 bb’s it would should further? Confusing but chrono is always with 0.20bb from field even bolt snipers and such.. using 0.28 right now at half hop or so


how did u calculate the jouls


That's why you need to wear protection.
Don't play if you don't want to get hit.
Cheaters will be cheaters. Even if you do it by joules if the players will not follow engagement distance somebody will still get hurt.


I am dividing to pick up a 2.8 joules spring or a 5 joules spring from novritsch.do the 5 joules spring harder to pull back the bolt or 2.8


this dude is parched the whole video lmao

Adrian Travelian

There is something to add on my side. Heavier bb´s are able to retain more kinetic energy throughout the trajectory. A 0.20 will lose more energy through the trajectory than a 0.40.

Shirl Bristow

Doesn’t seem like a real works test.
But it’s consistent with its self.

Nathan Franklin

So the only way to intentionally joule creep would be to use a lighter weight bb to chrono, and a heavier weight bb to play right? Not planning on doing this at all btw, just got my first hpa set up and heard about joule creep. Still lost...

tal weiss

this explanasion is horrible

Travis Carver

AMS does not chrono in joules. They chrono aeg with .20 and gas/hpa with .32 but still go off of FPS

Julio Rodriguez

+gun gamers thanks for making joule creep easy to understand! Hopefully the fields near me can start doing crono in joules it sounds like it'll keep the game more friendly and safer for the younger crowd.


I love this video. Thanks for the explanation. What's the supressor/chrono combo called? And how much does it cost?


Love the quality vids keep it up!

Frankie Lopez



how big is 1.7 joule in airsoft?

Coalition Crew

Great video!

meow meow d

can high joules penetrate tin can or galvanize iron sheet?


Interesting, because I can see the joule creep in all my green gas guns even with 0.25. Maybe your gun is optimized for 0.25 and 1.2 J .Otherwise it's pretty much what I see too. The joule creep is higher if the gun's inner barrel is longer, my KJW M700 reaches out to whopping distances because with 0.45 BBs it jumps up to 4 J (from 3). But interestingly it's CO2 mags don't do it.


@ the games i go to in europe every gun has to pass the chrono test with the players own BBs. BB weight will be set and the joules tell if the gun is allowed or not. sometimes new ppl on the field have to do an extra chrono test @ 0,25g BBs.


I think the system I know of here in Sweden is better, we chrono with the weight bb we're using.

Joule chart

Share on facebook
Share on twitter

Joule and FPS: An Explanation of the Differences and Joule Creep

5 348 views | 2 Aug. 2014

This video was meant to

This video was meant to educate airsofters about joules and FPS, the differences between the two and joule creeping. It also explains why gas guns and HPA powered guns (such as polarstars) joule creep as well as the need to joule creep in DSG builds.

I realized I never covered how to measure joules while chronographing (although deductive reasoning will give you the answer). After chronographing someone's FPS with your standard round (normally 0.20g), chronographing the joules with their preferred (field) round will give you the amount of energy being passed through the BB. With this joule and a joule chart (or calculator), you can then convert over to FPS as needed.

Check out my Facebook page here:



Mate.. energy is constant because this is how physics says. The amount of energy that goes into a system will have to leave the system, as is or transformed. 
In this case the energy is the correlation between velocity and mass(probably there is a small amount of energy that bleeds out as heat... but let's keep it simple).
Theoretically a gun that shoots 400fps with .2g bbs will have aprox 1.5j. If you put 0.3g bbs in the same gun you will get around 328fps so the energy remains constant, at around 1.5j.

There are many problems with gas guns and HPA because :
- No one can control perfectly the amount of energy that goes into those systems. The gas regulators will let some gas to escape into the barrel in order to propel the bb but those are not very accurate systems.
- On top of that the propane for example will have probably 100psi at 40f and 145 at 90f.
- When you measure the speed of a gas or HPA system with 0.2 there is a big chance you'll get only part of the picture. You will certainly have a lot of unspent energy because that very light projectile will leave the barrel way too fast in order to capture everything. So you'll probably have 1.5j gun when you measure it with 0.2g and a 2.2J one when you measure with 0.4g bbs .

On the other hand an electric airsoft gun will have 60cc of air no matter what because the volume of the cylinder is fixed.


Great video Khang!


Very informative video. However, what you say at 3:11 is incorrect. The amount of energy in the BB is not constant throughout flight - In fact it varies more than FPS does throughout flight. Kinetic energy is defined at K=(1/2)(m)(V^2). So a 5% decrease in velocity actually results in a 10.25% decrease in kinetic energy.

Other than that point, great video!

Erik Ostrom

Nice. Sharing this. Erik's polarstar at the start lulz.