[Lirimacora]

I hope I'm not offending anyone by making this thread.
Making this thread so other threads don't get hijacked about this subject.

Scheck has talked about this on the FB page and now in Geograd's thread ( http://www.airsoftsniperforum.com/32-general-sniper-talk/9824-want-know-your-max-distance-8.html ) and I would like to know more about the subject.

Quote from Scheck:

"I also follow the same line of thought as Geo: the more joules I fire with the better.

THIS is also why I run a shorter barrel, at only 400mm, as shorter barrels allow for "energy creep"

Energy creep is a term that describes why I have a higher muzzle power (joules) with higher weight BBs than lower weight BBs.

What does this mean? Well, when I chrono with .2gram BBs, I'm field legal at 498fps which is 2.26 joules of energy.

BUT when I chrono with .4gram BBs, my muzzle energy is a massive 2.66 joules. That's an extra .4 joules of energy from the same rifle. This rifle is still field legal according to field rules, but has a much higher energy rating now. If I convert 2.66 joules back to .2gram, that's roughly 550fps!

So why is this? I'm not 100% sure, but I believe because the .2gram BBs accelerate so quickly, they leave the barrel before all of the air from the cylinder "gets behind it". Because the heavier BB is more massive, it takes longer to accelerate from 0 and therefore has longer time for greater air pressure build up behind it.

This is just one "trick" that allows me to out-range other players on the field- energy creep gives me that extra little bit of oomph."​

I've heard similar statements here in Denmark. Guns with a shorter barrel and heavy BBs gets a better output (higher joule and effect down range).
No I don't have any facts to back me up. That is why I've made this thread. To hear what others think and maybe someone has facts and wants to share.

About your little "trick" Scheck. Here in Denmark more and more fields are going to rate a gun by its joule output, with the BB weight you are going to use and the hop up set. This comes from the Danish MilSim rules: http://milsim.dk/rules/up/danish_milsim_rules_v3.1_english.pdf

 

[Scheck]

Yeah, I hear that more sites are going for that, and I would like to see a joule limit come into effect here too. It would mean that I couldn't use my little "trick" any longer, but it IS safer.

A recent site has banned any BB other than .2gram bb because "Heavier BBs can penetrate skin easier". This sounds like tosh to me, so I believe if they'd have just put a joule-limit on rifles, that would be more appropriate.

but yeah, to back this up
These results were taken with the hop up excatly the same. I can't take my hop all of the way off, but it was as low as possible

here is my result on .2 gram BBs:



and .4 gram BBs:

 

[Lirimacora]

As I recall, you use an SVD? Aeg, hpa, co2 or ba? Don't know if that can have a factor in the equation? Might as well get everything out.

Sendt from the field with tapatalk

 

[Scheck]

ah yeah.

Spring powered vsr10, with excellent air seal and smooth air flow.

+-1fps around 494fps

430mm laylax inner barrel, with firefly hard hop rubber

Laylax cylinder and internals

Madbull .40gram BBs

Xcortech chrono

 

[Dimitri MdP]

Yeah, I hear that more sites are going for that, and I would like to see a joule limit come into effect here too. It would mean that I couldn't use my little "trick" any longer, but it IS safer.

Absolutely agreed. I tried to change my local community rules to Joule limit, not "FPS with .20" limit for a long time.. then I applied that "if you can't beat them, join them" kind of thing, so my actual gun is one of the greates energy creepers I've ever seen, as it shoots 3.34J when chronoing (600FPS with .20s), and a little over 5J when out in the field (520 FPS with .40s). Of course I use twice the MED required by the rules, but I still think it would be better and safer to use a Joules limit.

........................................

"Energy creep" is a big deal in our gun's range, coming second only to a great hop up configuration. To increase it you can use:
- The heavier bbs you could find (for snipers, .43 or .40s if you don't like black bbs).
- A correct piston compression pattern. (look for acceleration patterns)
- A better cylinder to barrel volume ratio. It's not the shorter barrel, it's the relation between the volume (ID and lenght) of your barrel vs the volume in your cylinder.
- CO2 guns. As the CO2 expands unlike compressed air (either from HPA setup or the standard springer/AEG), it provides a greater push when using heavier bbs.
- If your field chronoes without hop up applied, you can use a hop up setup that loose a lot of air between the bb and the rubber when no hop is applied, but provides more FPS when you dial in the correct configuration. Flat hops are great for that.

And a lot of other little details.

 

[Scheck]

- A better cylinder to barrel volume ratio. It's not the shorter barrel, it's the relation between the volume (ID and lenght) of your barrel vs the volume in your cylinder.

Yeah, this I understand and you're right of course, but seeing as vsr cylinders are generally of a set volume across the board (other than bore-ups from PDI), I don't count them as a variable, unlike barrel volume! Hence why I say "a shorter barrel". I was just taking a verbal short-cut.

 

[FalloutState]

I hate to be the pessimist, but I see this opening a gateway to some serious injuries by abusive players. Still cool, but still dangerous.. As Dimitri's story proves. Not saying you guys abuse it, though I can't support the idea of bypassing the safety regs even when used in a safe manor, especially when I know someone out there would use this far inappropriately. It provides a perfect way to "cheat" the chronos and use a gun in game that far surpasses a safe energy level.

..Also talk of guns over 550/.20 in game is against forum rules, but that isn't my concern here.

 

[Libelle]

Joule creep certainly happens, and I have documented it too. It also totally stands to reason. It is something we factored for at the field here, and with AEGs any creep was within tolerances. But a I hear the recent additions of many high-end gas guns has made the creep out of hand (a guy got a bb buried through his nose), well beyond the amount we were expecting with AEGs.

From every ounce of physics intuition I have, I have to say the heavier BB being more dangerous on impact is crap; given the same surface area, X-Joules is always X-Joules, a 0.20 at X-Joules is just as stingy as an 0.40 at X-Joules.

Regulating this is just as tricky if you gauge by FPS or Joules. Really how you measure it doesn't really matter, since either way you have to track the force that will be used on a field. So, I think the best method is for the chrono to use a heavier BB than 0.20 and when choosing the safe limit, remember that it must be safe at point blank, at just beyond the MED.

 

[Lirimacora]

I want to make something clear. I am against the usage of "energy creep". I do not like cheating and in some ways "energy creep" is cheating, or bending the rules to your advantage. I would like to see the rules change so it's not possible to use this trick.
When you do your chronos, it should be done with the desired hop up and BB weight and it should be the joules that decide your MED.

If the shooter is ignorant or just plain stupid, he will not act as his rifle is shooting 4J instead of 2J, he will shoot with the MED for 2J and maybe end up hurting someone. That could hurt the sport and create even more laws to forbid airsoft.

Then why did I want to know more about this "energy creep". Simple, you cant beat something you don't understand. Make it known to people that this is possible, then maybe someone with the capability to do something about it, steps in and change the rules before anything bad happens.

And also, I'm curious. Knowledge is great, even if its "bad" knowledge.

 

[FalloutState]

I want to make something clear. I am against the usage of "energy creep". I do not like cheating and in some ways "energy creep" is cheating, or bending the rules to your advantage. I would like to see the rules change so it's not possible to use this trick.
When you do your chronos, it should be done with the desired hop up and BB weight and it should be the joules that decide your MED.

If the shooter is ignorant or just plain stupid, he will not act as his rifle is shooting 4J instead of 2J, he will shoot with the MED for 2J and maybe end up hurting someone. That could hurt the sport and create even more laws to forbid airsoft.

Then why did I want to know more about this "energy creep". Simple, you cant beat something you don't understand. Make it known to people that this is possible, then maybe someone with the capability to do something about it, steps in and change the rules before anything bad happens.

And also, I'm curious. Knowledge is great, even if its "bad" knowledge.

I could see your motive, I just worry about the entire sport along with the safety of others when people (like Dimitri) show examples of such a high in-game energy and admit to still playing. Sure, he said he plays at a safe MED, but others may not. Either way though, it's still twisting the rules and causes safety concerns as well as concerns for the entire sport. I can't imagine lawmakers would like hearing that people can so easily cheat the system, and in some countries the law itself.

Surely my concerns are well understood, I'm not attacking anyone in specific, just voicing my concerns for the safety and continuation of the sport we all love.

 

[Dimitri MdP]

Surely my concerns are well understood, I'm not attacking anyone in specific, just voicing my concerns for the safety and continuation of the sport we all love.

I understand, and I have the same concern. I spent two years trying to change that rule, but every single time I posted about this topic, someone from our community's directive committee would close the thread and ask me not to speak about it in public. Then I've found out they were using it themselves. Furthermore, one of them have moded the hop chamber to loose a lot of air when not active (as we crono with no hop) but seal a lot better when dialed in, so he was cronoing 600/.20, perfectly legal down here, then it would reach 650~660/.20 when setting the hop where he would use it.
It's time for elections, so I'm hoping the next Committee will address this issue instead of abusing it.

That being said, energy creep is real, whether we talk about it or not. The whole reason for KJW M700 popularity is the energy creep it gets just from using gas. And somehow the G&G G96 takes that to a whole new level, as it shoots >500/.43 right out of the box (my gun is just a regular G96 with mods for precision and a CO2 setup for a power downgrade and better consistency, I did nothing for the purpose of energy creeping) But every G96 owner out there is a big energy creeper, the only difference is that most of them don't even know it. And that's the dangerous part. And so are a lot of other popular guns and mods.

On most places the rules are set considering this issue, but as I said, the only way to ensure players safety would be to set a Joules limit cronoing with the bb weight and hop seting we are going to use in the field (not "FPS with xx grams" like most places currently have)

 

[dobey]

From every ounce of physics intuition I have, I have to say the heavier BB being more dangerous on impact is crap; given the same surface area, X-Joules is always X-Joules, a 0.20 at X-Joules is just as stingy as an 0.40 at X-Joules.

I agree 100%, the problem is the heavier bb carries its energy farther. If a gun fires a 0.25g bb at 3.52j muzzle energy, and another fires a 0.43g bb at 3.52j muzzle energy they will both hurt the same at the muzzle. At 100 feet it is a much different result.

To combat this as a field owner/event organizer you simply need to chrono the airsoft gun with the bb weight the player will use.

You also have to set the MED for the bb weight.

An airsoft sniper with a 3.52j muzzle energy will have an MED of 70 feet (21 meters) at my local field, but the same gun using 0.43g bb's and a muzzle energy of 3.52j would have an MED of 115 feet (35 meters).

The heavier bb carries its energy farther. It also is slower to accelerate and has a longer time in the bore under pressure.

So chrono with what you use, set the limit by joules at the muzzle, and set the MED by the bb weight and muzzle energy.

 

[Dimitri MdP]

the heavier bb carries its energy farther

Why?......

 

[dobey]

Great place to start for an answer to that question: ATP - The Airsoft Trajectory Project

 

[Libelle]

Why?......

Inertia. Though they might have the same force in them, the heavier BB's has a higher inertia and thus is more resistant to forces acting on it (air resistance) than a lighter bb.

I agree 100%, the problem is the heavier bb carries its energy farther. If a gun fires a 0.25g bb at 3.52j muzzle energy, and another fires a 0.43g bb at 3.52j muzzle energy they will both hurt the same at the muzzle. At 100 feet it is a much different result. ...

Oh yes yes, but the inertia of the ball is a matter for the MED, not the chrono limit.

Giving different weights different MEDs is problematic. It is almost entirely unenforceable, but it means players don't know what to expect on the field. Let me take Player Bogey. Player Bogey is a young man, and when he plays he gets excited, and when he gets excited, he stops breathing as much or something and gets a bit stupid.

So, Player Bogey is on a field where most guys are using heavy weight bbs and highly tuned guns, and their MED is, say, 35 feet, as is his. He assaults something, and someone has his 0.20 CQB gun with a MED of 10 feet, and at about 15 or 12, feet. Which would be fair enough, but Bogey is expecting 35 feet. He gets cross. Many problems arise. Things get a bit punchy.

***

Joule Creep is a part of physics and will always happen in the gun. I think the best way is chrono with a heavier bb and ban guns that can not be regulated. There is no sympathy for the man who brings an untrustworthy rig, for he is known by his targets.

 

[Libelle]

I agree 100%, the problem is the heavier bb carries its energy farther. If a gun fires a 0.25g bb at 3.52j muzzle energy, and another fires a 0.43g bb at 3.52j muzzle energy they will both hurt the same at the muzzle. At 100 feet it is a much different result. ...

Oh yes yes, but the inertia of the ball is a matter for the MED, not the chrono limit.

Giving different weights different MEDs is problematic. It is almost entirely unenforceable, but it means players don't know what to expect on the field. Let me take Player Bogey. Player Bogey is a young man, and when he plays he gets excited, and when he gets excited, he stops breathing as much or something and gets a bit stupid.

So, Player Bogey is on a field where most guys are using heavy weight bbs and highly tuned guns, and their MED is, say, 35 feet, as is his. He assaults something, and someone has his 0.20 CQB gun with a MED of 10 feet, and at about 15 or 12, feet. Which would be fair enough, but Bogey is expecting 35 feet. So he gets cross. Many problems arise. Things get a bit punchy.

 

[Scheck]

Out of curiosity, what is the MAXIMUM amount of creep one may be able to achieve on a max 500fps rifle on .2g BBs?

I'm hearing a lot of "energy creep is bad", and I agree there are safety aspects that must be looked at, but will that extra .4joules of energy I gain at the muzzle make a massive difference in safety?

My maximum energy is still 2.66joules which isn't that large compared to many of you, and I have a 100ft MED, so i feel that I'm still "Playing safe".

I'm not bending the rules at all, my rules state 500fps on .2gram BBs, and hence my rifle is legal. I don't see it as cheating, I see it as another useful tool for knowledgeable snipers to utilise. In all fairness, most people DO utilize it, without even knowing about it...