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Help Me to Convince a Site Owner to Switch to Joules Please


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What I said -

 

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Its 1.3 joules, I think that's around 374 FPS with a 0.2g projectile. Sites tend to quote what Paul has said due to measuring equipment fluctuations, hop effect on the projectile and the effects of different weights of ammo (know as "joule creep"). As again I think its because if its over that power level the Police would class it as a section 5 Firearm and having one of those can come with years of jail time and hefty fines.

 

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374fps on a .2g bb is the limit that was set in law at which point a full auto Airsoft/bb toy become something other than a full auto BB/Airsoft toy .

joule creep only really happens when you are shooting heaver BBs at higher fps levels . firing a .43g bb from a airsoft gun that shoots 350fps on .2g is Not going to increase the impact energy of that bb strike by any noticeable amount .The .43g bb would be travelling slower and not as far .

All modern chronographs calculates the joule energy from the pre set BB weight and all sniper are fps tested which also calculates joule energy on the bb weight that will be used in game and any hot gun is not allowed in to game.

Full auto aeg limit 350 fps .2g bb

DMR limit 450 fps .2g bb

Sniper rifles 2.5 joules max on BB weight used in game

 

 

Any help please chaps?

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Probably best to do some actual testing to show what results you can get.

 

Strangely they seem to accept joule creep effects for sniper rifles, hence menasuring on the BB weight used, but not on any of the others.

 

Does the site allow HPA?

If so, that might be the easiest way to test and demonstrate it.

 

I know one of my local sites insists on sticking with the "chrono on a 0.2", and I could very easily abuse this for joule creep in my bolt actions if need be, but I understand it enough to account for that.

I'm certain that there are plenty of players running around with theirs firing 499.9fps on a 0.2, but creeping massively once they get in game.

 

Whether you'll be able to get them to change their mind is another thing, however.

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I'm sorry but I don't quite get the context. Do they chrono test on 0.2g only and not on the weight the player is using?

 

If that's the context, I agree with Hudson's suggestion that doing tests with different weights to illustrate joule creep would be a good idea.

 

I would have thought liability insurance policies would be strict about energy limits.

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They have made half of the argument for you, but they may also be right that joule creep on their DMR & auto limits are negligible in comparison to their 

 

The argument is not to ‘test in joules’, but to test at the appropriate weight.

 

They may have already tested alternative weights and found that heavier BBs in ‘most general’ airsoft guns is negligible enough that the resultant joules are higher but within their acceptable limits.


Theres half an argument that a sniper player could put more effort into precisely fine tuning their RIF, though other players could be fine tuning ‘normal’ RIFs.  An argument remains that a sniper barrel would be longer which enables more acceleration along the barrel and could max out the imparted energy, in a ‘decent straight’ / ‘less friction’ barrel which then benefits from joule creep in gaining energy but not losing as much drag.  Making it more of an unknown, so they are less content with the ease of allowing some creep flexibility on the basis that it could be more than negligible 

 

Real life testing is required to prove / disprove 

 

Full auto aeg limit 350 fps .2g bb = 1.138j

374 fps .2g = 1.299j

DMR limit 450 fps .2g bb = 1.88j

499.9 fps .2g = 2.32j


If a 350fps .2 then fired a .43 without losing velocity then 350 fps .43 = 2.4468j

But the unknown factor of joule creep is that the energy imparted in the chamber isn’t directly compensated with a slower velocity directly in line with the greater mass

 

 

 

I’m reading it that they chrono test most on 0.2 as a standard, but then for snipers adjust the chrono weight setting to test with the actual playing weight 

 

This adds time to test every player at whichever weight (assuming the player knows and is honest) 

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It's a much better idea to be arguing that the site test a pew as it's intended to be used i.e on the ammo going through it in-game.

 

After that the unit you use becomes less relevant, although joules is easier to apply because the limit is the same whatever the BB weight and therefore less numbers / conversion charts are required thus making chrono clearer and easier for all concerned.

 

IF they're doing random in-game chrono's then joules must make that easier too?

 

I'd go with an argument that shows the site that there is a benefit for them to make the change, they want people talking about a great game day rather than moaning about hot guns and having to buy some 0.2's just for chrono.

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Sounds to me like the site owner either doesn't understand joule creep isn't a constant which affects all guns in the same way or is just too lazy to chrono properly. Yes it may take a little longer to get everyone sorted when chronoing with whatever ammo is used in game, but many other sites do it without a problem so it's obviously not impossible.

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I save this for checking, I guess technically he's correct.

 

*has a quick check there's no naughty info in my screeenshot.*

fps chart.jpg

Edited by ButcherBill
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28 minutes ago, ButcherBill said:

 

 

*has a quick check there's no naughty info in my screeenshot.*

fps chart.jpg

** has a quick nostalgia moment about when I used to have moderator privileges on a couple of forums and could see full edit histories

….. including deleted posts 

You are embarrassed that you were on a paintball site weren’t you ?!?!???

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2 hours ago, Tommikka said:

You are embarrassed that you were on a paintball site weren’t you ?!?!???

Not guilty, never been paintballing & zero interest in it, just trying to hide my porn addiction...DOH!

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9 hours ago, blobface said:

 

I never thought it's from ignorance, I was proven wrong by this site owner

A combination of that and laziness. Even if you don't want to mess about with changing settings on the chrono it only takes a few seconds to look at a chart like the one posted by ButcherBill 

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Tbh, joule chrono'ing isn't difficult.

 

Takes about 5 minutes to print out a strip with the raw fps figure that different common bb weights would be at the site limit.

 

Likewise, a few speedloaders with common weights to double check if you want to be real paranoid.

 

Or even if you don't want to bother with that, just keep the method exactly the same but use a heavier weight instead

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https://www.legislation.gov.uk/ukpga/1968/27/section/57A

Law is pretty clear. It is not 374fps at 0.2g, it is explicitly 1.3Joules.

 

However, it seems they may be correct that an AEG shooting 350FPS at 0.2g (1.14J) is unlikely to experience Joule creep that would increase up to above 1.3J. Though a DMR or Sniper may be likely.

The only data I've found on joule creep in airsoft is this reddit post from 10 years ago https://www.reddit.com/r/airsoft/comments/29wi1s/joule_creep_testing_results_various_guns_and_bbs/
 

The data they found is as follows:

image.png.33559baf69217313d0c471ddf40df1ff.png

The mid-range AEGs and pistols tended to have very little joule creep from 0.20g+ (or even negative sometimes), however the DMR (SR-25) and sniper (VSR) did show significant joule creep.

 

image.thumb.png.55653c3386590fea9857cf2472c7d4a0.png

 

image.thumb.png.3289ff45564966383bb938ba777661c2.png

The DMR increases in energy ~34% from 0.20g to 0.40g. If we were to assume that this DMR were at your site and were shooting at the site limit of 450fps at 0.20g, (1.87J), when loaded with 0.40g bbs, it would be shooting at or just above the legal limit of 2.5J. When you consider that it is also firing in semi-auto, that is not safe or fun. The sniper's increase is also a concern but your site already appears to have addressed that.

 

Generally, it seems that the rules that this site has for AEGs should be fine, as is the rule on snipers. However, the DMRs should certainly be chrono'd in Joules on the BB that will be used, the same as snipers are at thissite.

 

 

It would be nice to have some more up to date data on this with more varied guns and more information such as piston volume.

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Mint, when he says "AEG" he means stuff firing in full auto in this context. My GDR15, GBBR and HPA systems with 400mm barrels all Chrono over 1.3J if I set them up to read 350FPS with a 0.2g BB and then change to a .4g BB. I am not 100% sure on the physics but I guess the projectile stays in the barrel longer and the fact you have more propellant behind the projectile that can expand VS a cylinder in a traditional AEG might be the case. 

 

Thanks for the reply.  

13 hours ago, Cannonfodder said:

If that's how they react then fuck them off and find another site, preferably one who they know what they're doing and don't throw a tantrum when questioned

 

From the photos it gets around 15-20 players. Was looking for the nostalgia of playing at Ambush Adventures Chobham from the early 2000s but I guess it was not to be :) 

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8 minutes ago, Chev Chelios said:

am not 100% sure on the physics but I guess the projectile stays in the barrel longer and the fact you have more propellant behind the projectile that can expand VS a cylinder in a traditional AEG might be the case. 

 

Pretty much, gbbr's/hpa's can just keep sending gas until the bb leaves the barrel (when setup to do so/with an adequately long barrel), longer the bb takes to leave the more gas is sent the more energy is added.

 

Aeg's have a fixed starting energy, so if the bb takes longer to leave the barrel it doesn't have any more energy to gain, as the spring just pushes the bb out as fast as it can.

 

The spring bolties are a bit more confusing, but essentially by having a heavy piston slowing the rate of energy being made available to the bb, meaning that a lighter bb can escape the barrel before all the spring energy is released.

 

Theoretically aeg's would joule creep too, but the amount is sufficiently little to be insignificant compared to other variations.

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2 hours ago, Chev Chelios said:

I am not 100% sure on the physics but I guess the projectile stays in the barrel longer and the fact you have more propellant behind the projectile that can expand VS a cylinder in a traditional AEG might be the case. 

You're spot on about gas guns. I guess the effect isn't as obvious as muzzle energies are lower in full auto AEGs, rather than the method the bb is fired. After all the only difference between a spring powered bolt action and AEG is that one is manually cycled and the other uses gears and a motor

Edited by Cannonfodder
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On 22/08/2024 at 14:15, Cannonfodder said:

You're spot on about gas guns. I guess the effect isn't as obvious as muzzle energies are lower in full auto AEGs, rather than the method the bb is fired. After all the only difference between a spring powered bolt action and AEG is that one is manually cycled and the other uses gears and a motor

This is true altho any gun with an excess of energy in the spring will create creep with heavier bbs, just because the extra time the bb spends in the barrel soaks up the extra energy. DMRs and BASRs have typically longer barrels and larger effective cylinders, stronger springs too, but for creep its just the excess energy that matters and the time to utilise it.

 

 

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