Chrono'd over 1 joule?!?!?!? How?

pokermonkey

Was out in Rebarn today with my CA8-2, went to get it chrono'd and low and behold it was consistantly chrono-ing (is that a word) at around 1.2 joules.
A bit odd as i've only skirmished it once before and it was under 1 joule that time.
Haven't changed a singly thing on the gun, and have only fired about 100 rounds since the last time i skirmished.
The lads up in redbarn rightly didn't allow the gun out, but can anyone come up with a reasonable explanation why it has gone up - a bit of a pain in the rear for me now as i obviously have to get it it fixed! :mad:
Will be heading back to the retailer to get him to fix - but i've never heard of power going up before.

Toasty113

Did you change the hop up by any chance? And did you get it chrono'd at the same site before?

Witcher

pokermonkey wrote: »

Was out in Rebarn today with my CA8-2, went to get it chrono'd and low and behold it was consistantly chrono-ing (is that a word) at around 1.2 joules.
A bit odd as i've only skirmished it once before and it was under 1 joule that time.
Haven't changed a singly thing on the gun, and have only fired about 100 rounds since the last time i skirmished.
The lads up in redbarn rightly didn't allow the gun out, but can anyone come up with a reasonable explanation why it has gone up - a bit of a pain in the rear for me now as i obviously have to get it it fixed! :mad:
Will be heading back to the retailer to get him to fix - but i've never heard of power going up before.

Could be weather affecting it, weather and evironmental factors influence the chronoing of guns greatly, at the gathering 1 several people were over the limit even though the guns were sub 1J when they last used them. Humidity, air pressure etc affects it. How close was it to the limit the last time you chronoed it? Should always stay about 310 then you leave allowance for a small increase due to waether conditions.

Hivemind187

1) It may not have been chronoed properly the first time. there are dozens of things that the tester can do to faff it up.

2) The atmospheric conditions may have been radically different. this can cause wild readings due to sunlight contamination, ambient temperature, whether there is wind blowing through the chrono.

3) The test was done with a heavier or lighter BB causing a change in the result.

4) The original test may have been done with the hop swtiched on somewhat, this can have a huge effect on power in some guns.

5) Gremlins.

6) Slightly larger gremlins.

pokermonkey

yeah, it was chronoed there last time too. it was a little cooler and a little damper from memory. came in at 0.92 joules the last time i think. bb's were .20's both times.
it was coming in at around 1.15 - 1.2 joules with and without hop up on.
pretty big jump though i thought.
hope its not caput!!

pokermonkey

Hivemind187 wrote: »

5) Gremlins.

6) Slightly larger gremlins.

LOL, gremlins.... big gremlins!

NakedDex

Did you see the previous test being done? Did it seem like anything was different to this time. Even the lighting in a room can change the result if done incorrectly. Where was it chrono'd previously?

Witcher

pokermonkey wrote: »

yeah, it was chronoed there last time too. it was a little cooler and a little damper from memory. came in at 0.92 joules the last time i think. bb's were .20's both times.
it was coming in at around 1.15 - 1.2 joules with and without hop up on.
pretty big jump though i thought.
hope its not caput!!

Yeah thats a pretty big jump, not sure by how much the weather affected the guns in Galway, mght need a spring change to be on the safe side, the retailer should do it for free afaik.

Firekitten

How can it be caput, if its firing at 1.2 jules? erm.... isnt that the definition of WORKING?

a few posibilities...

Is there any chance, the first crono wasnt calibrated right? or THIS one wasnt?

The number of different readings my guns get is stupid...
Eliana my L96a1 for example...
My crono... calibrated... 495fps...
SYA crono: 450fps
F&O crono: 420fps
The fort crono: 370fps...
SYA again: 503fps...

These things change like crazy... id get them to check thier kit... guns dont magically go up and down in fps without a definate mechanical change to the operation.

And as for weather... ive really never seen a 30+ fps change EVER.... 5-10 yes... anyway, why dont Irish sites have a +-5 percent to account for crono and weather issues? Its used all over the uk to great effect...

pokermonkey

hmm, not sure if he has the expertise tbh, but will try all the same.
maybe he'll shout me a new one.... ha, unlikely!
i have the law on my side though!:D
just dissappointed though. really like the gun, and now i can't use it!

sorry - just having a bit of a rant.

pokermonkey

Firekitten wrote: »

How can it be caput, if its firing at 1.2 jules? erm.... isnt that the definition of WORKING?

a few posibilities...

Is there any chance, the first crono wasnt calibrated right? or THIS one wasnt?

The number of different readings my guns get is stupid...
Eliana my L96a1 for example...
My crono... calibrated... 495fps...
SYA crono: 450fps
F&O crono: 420fps
The fort crono: 370fps...
SYA again: 503fps...

These things change like crazy... id get them to check thier kit... guns dont magically go up and down in fps without a definate mechanical change to the operation.

And as for weather... ive really never seen a 30+ fps change EVER.... 5-10 yes... anyway, why dont Irish sites have a +-5 percent to account for crono and weather issues? Its used all over the uk to great effect...

in fairness to the lads, they chronoed it on 2 chrono's which were coming up with the same result. its definitly the gun unfortunatly.

i thought it might be caput, cause one of the guys said either the hop-up may be damaged, or some cylinder may have expanded or something (please excuse my over technical analogy there ahem)

Hivemind187

Firekitten wrote: »

And as for weather... ive really never seen a 30+ fps change EVER.... 5-10 yes... anyway, why dont Irish sites have a +-5 percent to account for crono and weather issues? Its used all over the uk to great effect...

Because there is no allowance for it in the law unfortunately. We dont choose 1 joule across the board happily, its simply that anything above this, according to the letter of the law, is a firearm.

Shiva

pokermonkey wrote: »

i thought it might be caput, cause one of the guys said either the hop-up may be damaged, or some cylinder may have expanded or something (please excuse my over technical analogy there ahem)

Sorry if this sounds a bit harsh....I'm not having a go at you, but just offering a little advice. You mentioned in a previous post that the "law was on your side". I wouldnt go into the retailer with an attitude, if I were you.

It already chronoed legal when you first used it, so its not like he sold you something hot deliberately, or through negligence. Just tell him what happened, and if its who I think it is, he'll look after you. But dont go waving your arms and quoting the law - it doesnt sound like he deserves that kind of thing

pokermonkey

Shiva wrote: »

Sorry if this sounds a bit harsh....I'm not having a go at you, but just offering a little advice. You mentioned in a previous post that the "law was on your side". I wouldnt go into the retailer with an attitude, if I were you.

It already chronoed legal when you first used it, so its not like he sold you something hot deliberately, or through negligence. Just tell him what happened, and if its who I think it is, he'll look after you. But dont go waving your arms and quoting the law - it doesnt sound like he deserves that kind of thing

completely agree. it was meant in jest. would never go into a retailer with that attitude. completely counterproductive.
But, if he told me to PFO, then i might bring it into the argument.:p

Evangelion

It could be as simple as one of the Chrono's needing calibration (do the sites have to do a regular Cal.?)

I was at Red Barn today too, and my Tavor chronoed at 0.96, same as my home one and the retailers, but I had another site Chono it at 0.84 yesterday

Firekitten

pokermonkey wrote: »

in fairness to the lads, they chronoed it on 2 chrono's which were coming up with the same result. its definitly the gun unfortunatly.

i thought it might be caput, cause one of the guys said either the hop-up may be damaged, or some cylinder may have expanded or something (please excuse my over technical analogy there ahem)

In 'fairness to the lads' WHICH of the two seperate times, did they crono it twice?

I didnt say both cronos were out... just that apparnely, one is, as you claim there is nothing changed on the gun. Ergo, it must be an outside factor.

Masada

was it new when it was first chrono'd?

if it was then its possible that te hopup has bedded in and when switched off it isnt protruding at all, when there new they tend to be on slightly even when the switch is off, the rubber needs to bed in.

its a hell of a jump in fps though, maybe 30fps or so on a .2g bb. could even be the conditions it was chrono'd in.

Hivemind187

Masada wrote: »

was it new when it was first chrono'd?

if it was then its possible that te hopup has bedded in and when switched off it isnt protruding at all, when there new they tend to be on slightly even when the switch is off, the rubber needs to bed in.

its a hell of a jump in fps though, maybe 30fps or so on a .2g bb. could even be the conditions it was chrono'd in.

Or potentially a combination of things?

I'm erringo n the side of chrono technique though. Easiest way to get a high reading like that I have found.

desertstorm

i had an aeg range between 250 fps and 300 fps with .2g's, and as far as i can tell it was simply down to the first time it was in my boot on a really hot day a while back when i was going to a site and then the next time it had been stored in a cool room for a good few days?

Firekitten

depends... it could effect the liquid state of the grease in the gearbox... but i cant see it effecting air density or spring power in the same method... but my engineering isnt my strong point... i just know HOW they work not why to the same detail...

To the best of my knowlage, the heat issue effects gbbs more... (boy does it)

if you have a 50fps variance... thats some pretty low tollerance in parts :S id be quite bothered if my aeg was jumping around that wildly... (5fps bothers me)

TheDoc

Or maybe its just a case that it was a hot gun from the start?

From my experience with the Red Barn lads, as has been echoed by a number of people I talk to, their chrono is extremely accurate and their chrono'ing is done in a decently controlled enviroment. And they use two chronos to sometimes dispell " your chrono is ****ed mate".

I'm going to take this opportunity to say well done to site owners who I've visited in the last few months who are doing Chronoing properly. Makes me feel much better going onto a site knowing I do not have to contest with hot guns.

Even if there was a slacking tolerance, I wouldnt mind. If 340fps was allowed on a site I wouldnt care, to let those obscure occurancies in aeg's and chronoing in different conditions allowed on.

But there law is the law, and unfortunately in this country I've little faith in the honour system and no doubt everyone would set their gun for 340fps, then moaning that they should get allowance for 350fps.

If your serious about airsoft you should go attend a UK event or get some feedback. The last big event I was at was Phoenix Rising 3 where NO ONE GOT CHRONOGRAPHED before the game started. Everyone was giving the benefit of the doubt and it was a superb atmosphere to be in. You know your playing good honest players. Ironically alot of the irish lads got chronoed and the marshal lold when he saw the 260 or so fps they came in at.

Firekitten

We do get cronoed a lot here... you get the usual Skangers trying to get away with 20 fps more because they think it makes them better...

that or stock acm guns they dont know HOW to downgrade or dont know its hot...

pokermonkey

TheDoc wrote: »

From my experience with the Red Barn lads, as has been echoed by a number of people I talk to, their chrono is extremely accurate and their chrono'ing is done in a decently controlled enviroment. And they use two chronos to sometimes dispell " your chrono is ****ed mate".

I'm going to take this opportunity to say well done to site owners who I've visited in the last few months who are doing Chronoing properly. Makes me feel much better going onto a site knowing I do not have to contest with hot guns.

+1

i'm bringing back to the shop shortly. if we can get to the bottom of it i'll re-post.
thanks for the suggestions.

desertstorm

i was thinking the heat might have loosend up the spring, but i have noticed that aeg having it's up and down days between 260 and 300.. maybe something else is at work here

Hivemind187

desertstorm wrote: »

i was thinking the heat might have loosend up the spring, but i have noticed that aeg having it's up and down days between 260 and 300.. maybe something else is at work here

Faulty air seal. Usual culprit for anything erratic in airsoft.

Firekitten

ptfe tape... win

Puding

if i have an aeg firing at a +/- 5fps either side would give be concern and i would be having a look at the gearbox or the barrel/hopup. i would be looking for a reason for such inconsistency

Firekitten

if we are talking about his.. yeah

but the uk +-5% thing is more to give space for little fps changes above the limit if your gun is at 328 normally... small thingsl ike crono inconsistancy etc.

Puding

ow i do not mean +/- 5 of the legal 1j limit, i mean +/-5 of the power im aiming for this is normally 310fps, unlike a large % of the irish airsoft market i do not see 1j as a target

normal go 310 to cover myself and i can normally out range with more accuracy someone shooting 325+ with the right hop up and barrel combo, just ask anyone at cork about the star l1a1 i built for my father

Firekitten

bingo...

FPS plays little in actual range or accuracy. it just helps it get there faster beyond 300.

I'll be selling my Vsr10 on here soon... only doing 320 but can put a bb out past the 70 mark in good conditions :P on a human size target :P

Stercus Accidit

310 ftw.

andros

I've manage to buy two hot aegs from Irish retailers and have to downgrade them myself. I would not even go it to the way how aegs are getting to Ireland and what fps they have before going to customer.

But there is plenty of factors that could affect your reading.

1. Chronos are not calibrated
2. Different bbs give you different readings (not always)
3. Dirty barell
4. Chronos are not working the way they should work (might be damaged)
5. You got Hot Gun

Like other lads said before me, sunlight contamination, weather, chronod on heavier bbs etc.

bullets

Sounds like we should go back to the Coke Can to Chrono since there
are waaayyy too many factors that come into play if you use an actual Chronographs

I've had some AEG's chrono Hot on one Chrono and Fine on another.

I've also had 2-3 which read Hot when months before were fine and all they were
doing was sitting in a wardrobe without being used.

I've had something jump from nearly 328 right down to 220-250 without touching
the AEG in any way, just Chronod at different times.

Had one Chrono consistently at 350 fps ended up taking the gear box apart
to cut a piece of the spring, the snips broke! and I never managed to get the
gear box back together and working ever again. So if I get any more that go
on the warm side it will be Nozzle drilling solution for me!


~B

Stercus Accidit

If you are chronoing.

- Use a decent chrono, if possible two different models, they can vary in calibration but usually have some bias towards lower readings for safety, regardless, if a gun comes in hot on one chrono you should downgrade it or pay for a downgrade. Using two chrono's if available is a good way to get a rough gauge of you aeg/gbb's power, but the only chrono that matters is the one that the garda ballistics division use. Play it safe and make sure your guns are under on any chrono you use, 20 extra fps won't make your game more enjoyable, it might land you in serious trouble though.

- Know how to calculate energy. You need to know the weight of bb, and apply the e=1/2mv2 formula, simply put you are after a reading under 100m/s(328fps approx) with a .2g bb http://www.arniesairsoft.co.uk/?filnavn=/articles/fps_limits/fps_calc.htm Have a look at that, energy calculator for different weights also, know what fps your weight of bb's limit is for 1 joule, or have .2's available to use in the chrono, most people know the limit for .2's. If you aren't a dab hand at physics, you don't have to be, just learn off the limit for the different bb weights.

- Know how to chrono. You want the muzzle of the aeg/gbb right up to the chrono, the law is based on muzzle energy, so the closer the better for an accurate reading, also make sure the barrel is facing straight down the chrono, an angled shot may yield a lower incorrect result. Light will affect the chronos sensors, if you find you get a weird reading, turn the chrono 90 degrees to the main light source (so light isn't directly shining down the chrono tube) and try again. If you can test inside do so or in some uniform light conditions, just bear in mind this can affect readings, so watch where you are reading, this seems to affect different chronos to varying degrees from what I've seen, but always err on the side of caution.

- Hop-up off. Turn your hop off, this device reduces fps when on, and the law will consider the guns power when the hop is off, not on.

- Multiple readings. There are many factors that will affect the guns power and the reading the chrono takes, air seals can be temperamental varying fps wildly, hop ups can be damaged, barrels can have debris in them, chrono's can be affected by too much light getting into them. You want several readings, if you are way below the limit a few shots should confirm this, if you are very close, you want to try alot of shots, even one over will result in an illegal device, don't chase fps, aim for 300 or so if you upgrade and remember a decent hop will do alot more good for you than 20 extra fps which will be lost to air resistance within a few feet of the muzzle anyway.


Just remember, if you don't understand e=1/2mv2 use http://www.arniesairsoft.co.uk/?filnavn=/articles/fps_limits/fps_calc.htm to know the fps limit for YOUR weight of bb. Energy is not = to fps, it is a product of weight and speed, so know the limit for your bb weights or test with .2g bb's knowing 328 is the limit. Remember chrono's should not be facing directly towards or away from strong light sources, this can affect the sensors. Remember hop off and barrel directly facing down chrono, muzzle as close as possible. And also, if its hot on one chrono, its hot, the other chrono could be the faulty one, and get a downgrade asap. Remember, weather can affect air density, air density will affect how the air piston in your aeg pumps out energy, so keep a buffer between your aeg and the legal limit.

andros

Stercus Accidit is right. To be on the safe side, take higher reading as correct one, but be carefull every measuring device have to be calibrated - and I'm saying that no as airsofter but as engineer from the QA point of view.

Washington Irving

Shiva wrote: »

Sorry if this sounds a bit harsh....I'm not having a go at you, but just offering a little advice. You mentioned in a previous post that the "law was on your side". I wouldnt go into the retailer with an attitude, if I were you.

It already chronoed legal when you first used it, so its not like he sold you something hot deliberately, or through negligence. Just tell him what happened, and if its who I think it is, he'll look after you. But dont go waving your arms and quoting the law - it doesnt sound like he deserves that kind of thing

I wonder who he thinks it is???:P

Shiva

SAULGOODE9 wrote: »

I wonder who he thinks it is???:P

Not me, anyway

Firekitten

'Cronoing over 1 Joule?!?!?!?! HOW?'



I want to know how this thread is still going on *facepalm*

pokermonkey

dropped the gun back yesterday.
the guy in the shop was very decent about it - no quibbles. said he'd take it back to the place he got it and would get it sorted.
good to see good retailers still exist - hopefully he'll still be around given the new laws which came in.
i'll post again when i hear back what the issue was.
cheers
claw

Dread-Lock

Firekitten wrote: »

'Cronoing over 1 Joule?!?!?!?! HOW?'



I want to know how this thread is still going on *facepalm*

I would assume because he's trying to make his gun legal. And most people would like to help, as the less hot guns going about (accidental or intentional) the better.
And I'm sure he also wants to understand why there was a sudden change in power levels. As I'm sure he doesn't want it to happen again.

Glad to hear you got it sorted pokermonkey. But you may find most Irish retailers very helpful with matters like this.

Dr_Pepper

Dread-Lock wrote: »

I would assume because he's trying to make his gun legal. And most people would like to help, as the less hot guns going about (accidental or intentional) the better.
And I'm sure he also wants to understand why there was a sudden change in power levels. As I'm sure he doesn't want it to happen again.

Glad to hear you got it sorted pokermonkey. But you may find most Irish retailers very helpful with matters like this.

I presume its due to this.
*** Airsoft Forum Charter *** - Updated 07/06/2008
* There will be no discussion of airsoft greater than 1 joule.

Tbh this thread needs to disappear.

Witcher

Dr_Pepper wrote: »

I presume its due to this.
*** Airsoft Forum Charter *** - Updated 07/06/2008
* There will be no discussion of airsoft greater than 1 joule.

Tbh this thread needs to disappear.

Why? There's nothing to hide.

It's better people see we're trying to keep within the law and work to keep guns <1J than hiding the offending gun and saying "oh noes teh h0t gun, how do I fix it?".

If the DOJ read boards like they supposedly do, seeing people being responsible with hot guns is better than burying our heads and saying "no no no hot guns don't exist" when they clearly do, this case is by accident not design, mistakes happen and resolving them is key.

This thread has run it's course alright but banning discussion of a hot gun and how to downgrade it is crazy but that's the charter's fault.

BBones

Blay wrote: »

Why? There's nothing to hide.

It's better people see we're trying to keep within the law and work to keep guns <1J than hiding the offending gun and saying "oh noes teh h0t gun, how do I fix it?".

If the DOJ read boards like they supposedly do, seeing people being responsible with hot guns is better than burying our heads and saying "no no no hot guns don't exist" when they clearly do, this case is by accident not design, mistakes happen and resolving them is key.

This thread has run it's course alright but banning discussion of a hot gun and how to downgrade it is crazy but that's the charter's fault.

Have to agree! Ignorance is'nt the answer. education is!:rolleyes:

jayod30

Talkin about inconsistent chronos i have the madbull version and i don't find this reliable in any way shape or form. I have 3 AEGs and 2 GBBs which when chronod always give me various readings, all consistently jumping between 270 to 340 fps. Recently i brought them to <banned retailer> and they chronod them with the SKAN chrono the same type as the gardai and british police use for airsoft and ballistics testing and they all read under 1 joule and over 10 shots there was only a 5 fps differential so as i suspected my guns were fine. My point is in a controlled environment and by using a reliable chrono e.g. same type chrono as our gardai and customs then there can be no more arguments:cool:

Puding

stinks of a loaded post but i will bite...

alwasy found the madbul to be a very reliable chrono myself, infact we use one for the shop and site with no issues, maybe it was your chrono ?

jayod30

Maybe it is my chrono but your chrono in cork was givin very different readings on one of my guns last time i was down there aswell so i'm not totally convinced by them. Not lookin to argue with anyone but it sounds like some sites use different chronos which means inconsistent readings which isn't fair on a player who knows his gun is ok. In saying that Oz let me use it for an hour or so as over roughly 30 shots i think it shot over about 3 times so sense prevailed

Single Malt

Chronos need to be calibrated every once in a while. To be fair, anyone using a chrono with regards to a commercial interest should be required to have a calibration certificate for said chrono by law.

jayod30

I used my own one first a couple of days before i went to cork and found that bar my KWA M4 they were all shooting over at least 3 times over a 10 shot period. I then brought them to MIA and they tested them and then went over the read out with me and they were consistently shooting fine. In cork i mostly used my M4 as there was a problem with it and was only shooting at around 250 to 270 fps so knew no matter what type of chrono was used it would be ok. But when oz tryed the stubby killer i have it was shooting between 310 to 340 which i found was the same on my chrono but as i said already it happened only twice or three times. Simply put i know you don't have a choice you have to do what the site says but when it comes down to what the british and irish police use to test our guns or a madbull chrono i'll take the SKAN chrono any day.

bullets

OK I got to ask. Just how the hell do you calibrate a Chrono?

It cant be just a button push! it cant be something thats
a known constant to measure against as nothing is constant.

Can someone explain in detail just how a single piece of Chrono equipment is calibrated
to give an accurate reading with regards to airsoft equipment?

~B

tonky

Maybe somewhere in the world there's a master chrono.
Give us a break.
The sites are trying their best to stay within the law, as it stands, working with what's available and affordable
Sniping about calibration is not helping anyone imo.

*DOBBY*

jayod30 wrote: »

Talkin about inconsistent chronos i have the madbull version and i don't find this reliable in any way shape or form. . My point is in a controlled environment and by using a reliable chrono e.g. same type chrono as our gardai and customs then there can be no more arguments:cool:

I would have agreed with the fact that the Mad Bull can sometimes vary, we use two on site , But in this incident we got our second readiing off an Xcortech and they both read the same. So me thinks the chrono's are right and the very hot day in question,( air being thinner etc, all the science bit)had some effect on the Aeg.
We are getting the skan chrono from the uk, and I have a feeling that it too would have given us the same readings. It will be interesting to see when we get it.:)
I will let you all know asap.