Should more sites weigh the bbs during chrono?

[Rogerborg]

someone Chronos 1.2 j but the fps is 240 and they said the bb weight is 0.28 they lying cos a 0.28 at 1.2 j would chrono at 300/310 fps at 1.20 j

 

[Tommikka]

its combination joules and weighing bbs, joules is the constant  if the site limit for full auto aeg is 1.2 j and someone Chronos 1.2 j but the fps is 240 and they said the bb weight is 0.28 they lying cos a 0.28 at 1.2 j would chrono at 300/310 fps at 1.20 j , you would need to then  weight to confirm ,

so technically they have passed chrono but have lied about the bb weight ,if there lying about bb weight  what else are they being dishonest about?  

Joules are a measure of energy 

Chronographs measure velocity 

Some chronographs calculate the joules from the velocity based on the entered mass

 

[Cannonfodder]

its combination joules and weighing bbs

But that's not what you originally posted.

View attachment 150111

 

[ButcherBill]

Probably the busiest thread at the moment so I'll try and end it by saying... The Nazi's never weighed their BB's.

 

[Colin Allen]

Probably the busiest thread at the moment so I'll try and end it by saying... The Nazi's never weighed their BB's.

Of all their crimes, that is the wurst.

 

[LMKipper]

I think someone has just used a public forum to realise they don’t know how a chrono works. 

 

[Lyndication]

Clearly the answer is for every site to buy a sub-Joule resolution Strain Gauge to accurately measure actual impact energy, combining it with a chronometer to measure the velocity, and thus infer the actual BB weight.

I'm sure the very cash strapped Airsoft sites we have will just get right on this, it's only a couple of grand in precision measurement equipment.

 

[Adolf Hamster]

Clearly the answer is for every site to buy a sub-Joule resolution Strain Gauge to accurately measure actual impact energy, combining it with a chronometer to measure the velocity, and thus infer the actual BB weight.

I'm sure the very cash strapped Airsoft sites we have will just get right on this, it's only a couple of grand in precision measurement equipment.

[Rantmode]

Or buy a few dozen speedloaders and bb's in the common weights.

Or a set of digital scales.

Or invest in some tape to write the fps readings for different bb weights on the chrono

Or just memorise the site limit for common bb weights.

Or read about joule creep and what it means.

Or spend ten minutes googling why fps and joules are different things.

Or take the chrono with them and randomly spot check players

Or re-chrono players when they're complained about.

Or actually kick players off when they do get caught.

We dont need airsoft sites to fully understand the intracies of physics as they pertain to airsoft pews. The community has done that and served up practical solitions on a platter and even then the majority simply cant be bothered.

[/Rantmode]

 

[JVacation]

When I wrote this post a couple days back I did not expect it to cause so much traction! 

 

[ButcherBill]

When I wrote this post a couple days back I did not expect it to cause so much traction! 

So you didn't wait to see your grenade go off?

 

[mrfoxhound]

Joules are a measure of energy 

Chronographs measure velocity 

Some chronographs calculate the joules from the velocity based on the entered mass

yes but the joules are not gonna change ,

But that's not what you originally posted.

View attachment 150111

both post are relevant  

 

[Rogerborg]

Clearly the answer is for every site to buy a sub-Joule resolution Strain Gauge to accurately measure actual impact energy

Is the Coke[*]can test a joke to you?

[*]and/or Sprite. Irn Bru cans do not work, being made of girders.

 

[Lyndication]

The joules do change

 

[LMKipper]

yes but the joules are not gonna change 

My friend - take this from someone who runs chrono at a site as a marshal: a chrono cannot 'measure' the joules of an airsoft gun. It cannot be used to detect someone lying about the weight of their BBs.

All a chrono does is measure the speed of the BB - it does not know the weight of the projectile or the energy it is carrying. Inputting the weight into some chronos allows it to calculate the joules based on the input weight of the projectile. If the weight input is incorrect, the subsequent joules calculation will be incorrect.

If a gun chronos at 310fps and the user claims to be running 0.25g BBs, the chrono will say the RIF is firing at 1.12j. If they are actually using 0.3g BBs, the chrono will still read 310fps and it will still say it is firing at 1.12j when in reality its more like 1.3j. 

 

[Colin Allen]

Is the Coke[*]can test a joke to you?

[*]and/or Sprite. Irn Bru cans do not work, being made of girders.

Having lived in Glasgow in the distant past, I am aware that it is the contents of Ian Bru cans that are made from girders.  I am also aware that it tastes even worse than Vimto, which, given what the latter is an anagram of, is hard to believe.

 

[ButcherBill]

Having lived in Glasgow in the distant past, I am aware that it is the contents of Ian Bru cans that are made from girders.  I am also aware that it tastes even worse than Vimto,

How dare you Sir... I demand satisfaction!

I choose .2 bb's at dawn Monday the eleventyth of Movember.

?

 

[Tackle]

 I am aware that it is the contents of Ian Bru cans that are made from girders.  I am also aware that it tastes even worse than Vimto

? but I love it, & hate vimto?.

 

[Adolf Hamster]

How dare you Sir... I demand satisfaction!

I choose .2 bb's at dawn Monday the eleventyth of Movember.

?

.2's? Cant be that mad then......

 

[ButcherBill]

.2's? Cant be that mad then......

I'm assuming they won't be chrono'd

 

[Tommikka]

yes but the joules are not gonna change ,

That depends - if the joules don’t change the velocity also does not change 

The joules as per the muzzle velocity is different from the energy imparted in the chamber based on many physics things happening along the barrel 

The energy imparted onto a BB in the chamber remains the same irrespective of the BB (or actually it might, because force has to be exerted to begin the momentum and a heavier BB will resist more than a lighter BB)

It accelerates down the barrel, and depending on the internal barrel size vs the BBs actual size could theoretically float on air, but will have friction or bounce around in the barrel, and also get some friction from the hop up before escaping into the open air

These various factors are generally called joule creep when a heavier BB does not come out at the ‘right’ slower velocity to match the equivalent energy.

The combination of different configurations / efficiency

Joules do change - which is of course the whole argument over with regards to chrono checking

After leaving the barrel different BBs and different RIF configurations can result in different performance in flight with some losing monentum gradually, some going further, some flying almost perfectly then suddenly dropping when losing backspin.