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Newbie clarification re: 1 joule

  • 02-06-2018 3:13am
    #1
    Registered Users Posts: 20 atlas01


    So I used the search function, found a lot of input from the past, but still its not 100% clear for me. Maybe 80%.

    My concern is, I bought an airsoft replica from abroad, bolt action sniper rifle. From my understanding, it is legal as it is firing at 318-326 fps using 0.2g BBs. Perfectly under 1 joule and none get beyond 328fps. Now, i dont intend to use 0.2 when on the field ofcourse. I tried to chrono it using 0.28g BB and it is constantly firing at 280fps which is 1.something joule.. i believe this is what they call joule creep? but only by a decimal. 1 joule should be at 277fps i think.

    Is my replica legal? Gun is completely stock. M90 spring installed. Most of what i read from previous posts is that RIF should be on or below 328fps using 0.2g BB so I am confused and surprised that mine was a tiny decimal above 1 joule only when you used heavier BB.


Comments

  • Moderators, Category Moderators, Entertainment Moderators, Sports Moderators Posts: 23,078 CMod ✭✭✭✭ Steve


    By my reckoning that would put it above 1J with the 0.28g bb, 280fps / 0.28 = 1.02J

    Technically, by the letter of the law that would make it illegal.

    See my post here for details:
    https://www.boards.ie/vbulletin/showpost.php?p=79685030&postcount=3

    What I would question on your testing is the accuracy of the chrono and the weight of the bb. For example, if the actual weight of the bb was 0.005g under nominal (0.275g) then it would be legal at 1J, conversely if the chrono was off by 1% then it would have the same effect.

    If you have a printout / report that says you had it tested with 0.2g bbs at less than 328 fps then hold onto that as evidence that the RIF is legal.


  • Registered Users Posts: 20 atlas01


    Thank you for the response. I've already cut my spring as I wasn't sure back then. I was surprised that the joule would increase as the bb weight increases.

    As for my testing, I used an XCoretech X3200 Mk3, 0.2g Blaster BB, ASG Cursed 0.28g BB. I have no other chrono.

    As for report, there was no print out, upon ordering you would choose which spring (with corresponding FPS) you would like to be installed. So I selected M90 ~ 320 FPS according to the website so it will comply by law. So I did my own validations thru my testing.


  • Moderators, Category Moderators, Entertainment Moderators, Sports Moderators Posts: 23,078 CMod ✭✭✭✭ Steve


    Most retailers and sites will give you a report if you ask them, this is what I was referring to. Your own testing in not likely to be accepted if there is a question on legality but an independent report would hold more sway.

    I'll admit, I'm not so savvy on the ins and outs of the equipment used, there are more knowledgeable people here than me that can advise you.


  • Registered Users Posts: 20 atlas01


    You're a great help Steve! Cheers! I'd better be safe than sorry. I'll try to ask for a certification though it might be from a a similar model with similar spec (spring) as I have the actual item already with me now. Thanks Steve!


  • Moderators, Category Moderators, Entertainment Moderators, Sports Moderators Posts: 23,078 CMod ✭✭✭✭ Steve


    To be 100%, you need to have your RIF tested, as I said any retailer or site you want to use it on will do it.

    For example, if you were to sell it on the adverts forum here, the only acceptable proof it was legal would be from an independent test.

    Glad to be of help :)


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  • Registered Users Posts: 36,082 ✭✭✭✭ ED E


    The bit we don't like to talk about is energy output isn't entirely fixed.

    A GBB that fires 0.99J at 12*C might shoot 1.03J at 28*C. Add red gas and you're even higher output.

    What about my 0.9J GBB. I swap mag for a C02 mag and its suddenly 1.2J.


    A change of hop rubber might make that gun legal. Leaving it cocked for 5hrs before chronoing will make it legal.
    To be 100%, you need to have your RIF tested, as I said any retailer or site you want to use it on will do it.

    For example, if you were to sell it on the adverts forum here, the only acceptable proof it was legal would be from an independent test.

    Thats still arbitrary tbh. If you want to be legally sure that you are legal a calibrated chronograph is what you need. No site/retailer has one, some rifle ranges might just and the Garda Technical Bureau in PP definitely would.


  • Moderators, Category Moderators, Entertainment Moderators, Sports Moderators Posts: 23,078 CMod ✭✭✭✭ Steve


    ED E wrote: »
    Thats still arbitrary tbh. If you want to be legally sure that you are legal a calibrated chronograph is what you need. No site/retailer has one, some rifle ranges might just and the Garda Technical Bureau in PP definitely would.
    Accepted, but if best efforts available are made to ensure compliance, that's all anyone can do.


  • Registered Users Posts: 399 ✭✭ J-W


    Hi
    Unfortunately it is illegal in its current state.
    Any site you play at will test with .2'S and you'lol be grand and allowed play.
    I personally wouldn't care if you shot me with something 1.0X joules as the pain to me and performance gain to you is negligible.
    New springs will "bed in " and loose a bit of fps over the first 1000 or so bb's. With the numbers your quoting I figure you'll be legal after bed in. You can speed up the process by cocking the gun to compress the spring and leaving it like that over night / or longer. Downside is every spring is different and it my go too low.


  • Registered Users Posts: 31,463 ✭✭✭✭ Gatling


    ED E wrote: »
    If you want to be legally sure that you are legal a calibrated chronograph is what you need. No site/retailer has one, some rifle ranges might just and the Garda Technical Bureau in PP definitely would.

    Actually several sites and retailers use Skan calibrated chrono's and have done for a good few years now .

    People know their outputs and limits with aegs and gas doesn't mean people will stick to the limits ,for years we've seen this obsession in airsoft to hit exactly 328fps as if it's something special or makes their guns better ,
    It doesn't

    Langley , Virginia



  • Registered Users Posts: 20 atlas01


    Cheers for the replies everyone!

    I completely agree with you J-W and Gatling. Hitting a bang on 328 FPS is really negligible. I am fairly new to the sport, and I personally dont mind having a replica shooting at 300-315 fps as that is what most replicas here are shooting at. I honestly prefer that. Having a couple of FPS as allowance before hitting 328 really helps especially on a bolt action that could really produce joule creep.

    I bought a GBB pistol from a local store here, it was shooting at 280-310fps a month or two ago, but when I tried it a couple of days ago, man I was surprised that it gave me a very crisp blowback (which was unusual for my full metal m9 compared to my plastic slide hi-capa) with FPS beyond 328. Temperature really does matter on GBB.


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