FPs ok - joules too hot?

[SBoardley]

The law does not mention weight, only energy:
 

The permitted kinetic energy level is—

(a)in the case of a weapon which is capable of discharging two or more missiles successively without repeated pressure on the trigger, 1.3 joules;

(b)in any other case, 2.5 joules.”

Dunno about that mate 

View attachment 80361

 

[snuff]

Agree with your suggestion of people getting their own chronographs.

The issue then becomes which chrono?My ICS will chrono on my Xcortech @310 fps but at a site I visit their Nuprol shows @ 285 fps.

 

[colinjallen]

Dunno about that mate 

View attachment 80361

That is UKAPU's statement, not the law; what I quoted IS the law.

The issue then becomes which chrono?My ICS will chrono on my Xcortech @310 fps but at a site I visit their Nuprol shows @ 285 fps.

Nuprol...

 

[Adolf Hamster]

The issue then becomes which chrono?My ICS will chrono on my Xcortech @310 fps but at a site I visit their Nuprol shows @ 285 fps.

that's its own kettle of fish.

one side of the argument is a players personal chrono won't be subject to the countless tube strikes, bb shards and damp storage conditions that a site chrono will.

the other side is the site chrono (wether it's correct or not) is the one that will define wether or not you're allowed to play.

the other approach to the argument is any cheap chrono that isn't properly calibrated should be deemed useless.

as a practical term, if you can't access 2 or more chrono's that give agreement for a particular pew (under the same conditions that is, so same gun, same ammo etc), go with whichever one reads highest to be safe.

it's part of the reason why you don't want to necessarily push to get a gun to be right on the limit, as it just takes a site chrono to be over-reading by a couple of fps for you to be turned away.

 

[SBoardley]

That is UKAPU's statement, not the law; what I quoted IS the law.

I see what you are saying. I was talking in terms of joules creep; so the ukapu statement is actually slightly misleading?

View attachment 80378I’m slightly confused as this seems up to date?

 

[colinjallen]

I see what you are saying. I was talking in terms of joules creep; so the ukapu statement is actually slightly misleading?

Yes, as the law only mentions energy, if the police were so minded they could take your full auto capable airsoft gun that shoots at, for example, 1.14J when chrono'd on a 0.2g BB, load it up with the heaviest BBs that they can find and, if it now shoots at over 1.3J, you are potentially in very deep shit.

The FPS figures that UKAPU give are only valid for 0.20g BBs and, as such, pretty meaningless.

As far as the law is concerned, energy is the only thing that matters.

 

[SBoardley]

Yes, as the law only mentions energy, if the police were so minded they could take your full auto capable airsoft gun that shoots at, for example, 1.14J when chrono'd on a 0.2g BB, load it up with the heaviest BBs that they can find and, if it now shoots at over 1.3J, you are potentially in very deep shit.

The FPS figures that UKAPU give are only valid for 0.20g BBs and, as such, pretty meaningless.

As far as the law is concerned, energy is the only thing that matters.

I understand this, as I have air rifles, and know that different grain ammo can impact joules as stated on the rifles. 
but always presume that the benchmark was 0.2g so joule creep was irrelevant. 

 

[colinjallen]

I understand this, as I have air rifles, and know that different grain ammo can impact joules as stated on the rifles. 
but always presume that the benchmark was 0.2g so joule creep was irrelevant. 

Sites traditionally use 0.20g as the standard; however, the law does not, it uses energy, so if they can make your full auto capable weapon shoot at over 1.3J you have a big problem.

 

[SBoardley]

I think it would be really helpful to get some numbers up to maybe highlight the issues of joule creep. Because I feel at least for myself, a little education on the matter is useful. 
maybe get some sort of chart up of examples from different platforms? 
I’d give it a go but I’ve just had a house fire and lost a lot of gear including my chrono. Thank god I’m insured. 

View attachment 80385

 

[colinjallen]

I think it would be really helpful to get some numbers up to maybe highlight the issues of joule creep. Because I feel at least for myself, a little education on the matter is useful. 
maybe get some sort of chart up of examples from different platforms? 
I’d give it a go but I’ve just had a house fire and lost a lot of gear including my chrono. Thank god I’m insured. 

View attachment 80385

Oh shit!  That is bad.

I will try to find the data from some tests that we did a few years ago.

 

[SBoardley]

That would be great. I kinda understand more now, and understand better what @Rogerborgwas saying (apologies). I guess I’m old school, used to carry a bag of 0.20’s and a chrono to spot check punters- 328 +- 10%. Also most sites are still 350fps that we’ve visited. 
I shall definitely look at a chrono and bb weight differently now. Just took it for granted I guess. 

 

[Rogerborg]

so the ukapu statement is actually slightly misleading

It's the exact same problem as that which spawned this thread: an ingrained habit of thinking in terms of 0.2g because that's what used to be common in the dawn of airsoft time.

The law says nothing about BB mass.  It actually says "a missile (of any kind)".  The intent is clearly to limit what non-firearm airsoft guns could do in the hands of the malicious, rather than what us law abiding types intend to do with them.  The State could drop 0.86g steel BBs in there for testing.  We'd gasp in horror and say "you'll ruin the hop and barrel", but that's not a concern for Charlie Chav or the State.

On the issue of sites chronoing with 0.2g because it's quick and gives you some estimate of what the gun might be doing with the ammo that's actually in it, well, that's true enough. It would be equally quick to use 0.4g though, and it would be more likely to catch hotter guns.  It's not a panacea, but if you pick just one mass of BB to use, I'd advocate heavier rather than lighter.

 

[SBoardley]

@Rogerborg I completely get you. It’s exactly the same as air rifles be set below the max joule/ ft/lb limit; to allow for variance in pellet mass. 
thanks for the school men. I’m converted… chrono on a heavy bb in joules. Everything else is gravy. 

 

[Druid799]

I am just frequently amazed at how little many airsofters seem to know about what most would regard as the basics.

Very true it’s quite amusing at times when you see a player who you just assume would know the answer to XYZ but instead haven’t a clue  BUT equally there’s A very fine line between coming across as being surprised by this and coming across as a right arrogant twatwaffle ? 
its all about that first impression .

The issue then becomes which chrono?My ICS will chrono on my Xcortech @310 fps but at a site I visit their Nuprol shows @ 285 fps.

Aahh right , no theres a very simple answer to the discrepancy between the two of them , Xcortech is a trusted brand who make very reliably calibrated chronographs , where as Nuprol only sell shit products made by the lowest bidder they can find . ?

 

[colinjallen]

Very true it’s quite amusing at times when you see a player who you just assume would know the answer to XYZ but instead haven’t a clue  BUT equally there’s A very fine line between coming across as being surprised by this and coming across as a right arrogant twatwaffle ? 
its all about that first impression .

If you say so; we obviously live and work in very different environments.

 

[snuff]

 Nuprol only sell shit products . ?

Indeed....?

 

[Rogerborg]

Very true it’s quite amusing at times when you see a player who you just assume would know the answer to XYZ but instead haven’t a clue  BUT equally there’s A very fine line between coming across as being surprised by this and coming across as a right arrogant twatwaffle ? 

Mea culpa, I have a habit of doing that.

When I'm tempted, I try to think "What would colinjallen do?", then I do the opposite.

In this case, I do try to remember that sites are primarily responsible for educating players, and if they only talk in terms of fps, then what else are folk mean to think?

 

[Adolf Hamster]

In this case, I do try to remember that sites are primarily responsible for educating players, and if they only talk in terms of fps, then what else are folk mean to think?

wait, the sites are supposed to know more than the players!?!?

 

[colinjallen]

Mea culpa, I have a habit of doing that.

When I'm tempted, I try to think "What would colinjallen do?", then I do the opposite.

In this case, I do try to remember that sites are primarily responsible for educating players, and if they only talk in terms of fps, then what else are folk mean to think?

That is nice for you; I am rather amused that I get to live in your head rent free

Mea culpa, I have a habit of doing that.

When I'm tempted, I try to think "What would colinjallen do?", then I do the opposite.

In this case, I do try to remember that sites are primarily responsible for educating players, and if they only talk in terms of fps, then what else are folk mean to think?

I would rather hope that players would read, think and learn; we are primarily responsible for educating ourselves.  Foisting the responsibility onto sites is just laziness and a dereliction of personal responsibility.

Having marshalled at a couple of sites and played at loads, I would never rely on most site owners and managers for anything; obviously there are exceptions to that.

That would be great. I kinda understand more now, and understand better what @Rogerborgwas saying (apologies). I guess I’m old school, used to carry a bag of 0.20’s and a chrono to spot check punters- 328 +- 10%. Also most sites are still 350fps that we’ve visited. 
I shall definitely look at a chrono and bb weight differently now. Just took it for granted I guess. 

The plus side of the old 328+/-10% always baffled me; that just means that the limit is actually 361 rather than 328.

Once you get your head around it, Joules are the only way forward.

 

[AirSniper]

I will add my tuppence worth.

Joules remains the same energy input to the BB irrespective of your BB weight, heavier BB's like 0.25g travel slower and hold their energy better than a 0.2g BB.

A BB can not gain more energy than it has had imparted on it, that would break the laws of thermodynamics.

What I think is the problem is that your pistol chrono'd high because you have a possible leaky valve that is letting too much gas through which would throw the energy output up.