I was checking the velocity of my rifle to make sure I am below 12fpe before Worlds in November. I shot a number of times and my rifle came in at 11.55-11.7 fpe. Well within the limits. I did have one shot the jumped to over 12 fpe. I have the rule book printed off in front of me. I don’t really see a clear explanation on how they check rifles other than 3 shots. Do all three shots need to be under 12fpe, average less than 12fpe, is there and allowable variance, etc? I honestly feel like my rifle is legal and am not trying to cheat.
12fpe equipment check at Worlds.
- Thread starter BrazosbyNemo
- Start date
There’s something in aafta rules about a 2% allowance don’t know if it’s the same for worlds
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There is no leeway in WFTF for worlds. There is no 2% like AAFTA. You’ve got three shots, if one of those blows under 12 fpe you’re good if not, your DQ’d.
There is unfortunately zero margin. So be very careful.
There is unfortunately zero margin. So be very careful.
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No 2% allowance at the WFTF match.
The day before competition, you can take as many shots over the chronograph as needed to adjust below 12fpe.
On the competition days, your velocity will checked during the match. No adjustment allowed. If your 1st shot is under 12fpe, you passed. Otherwise, you get a 2nd try. If your 2nd try is under 12fpe, you passed. Otherwise, you get a 3rd try. If your 3rd try is under 12fpe, you passed. Otherwise, you are disqualified.
The day before competition, you can take as many shots over the chronograph as needed to adjust below 12fpe.
On the competition days, your velocity will checked during the match. No adjustment allowed. If your 1st shot is under 12fpe, you passed. Otherwise, you get a 2nd try. If your 2nd try is under 12fpe, you passed. Otherwise, you get a 3rd try. If your 3rd try is under 12fpe, you passed. Otherwise, you are disqualified.
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Thanks. That is what I needed to know. I feel like I am good. Since I will be shooting in a different part of the country, different elevation, unknown weather, I will just wait and see if I need to adjust anything after I get there.
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Three tries, that’s good. If you tune for exactly 12fpe, you’ll still have an 88% chance of passing. If your airgun has a 3fps standard deviation and you tune for 11.9fpe, you’ll have a 99.5% chance of passing. If you tune for 11.8fpe with 3fps SD, you’ll have a 99.998% chance of passing.
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"If you tune for exactly 12fpe"
12 FPE at the venue..... not home @4500 ft and currently 46 F
But thats doable! Have all the things needed and some ballistic program ideas to help get there.
Thanx Scott!
12 FPE at the venue..... not home @4500 ft and currently 46 F
But thats doable! Have all the things needed and some ballistic program ideas to help get there.
Thanx Scott!
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I’m also curious
What brand chrono will be used?
And how will it be calibrated?
Doesn’t altitude, temperature, humidity and barometric pressure all affect air density, which can have an impact on speed?
So… there might be different readings when officially testing during the match vs before or after the match…
With WFTC competition, they usually run 4-5 hours long…
Never mind…I’m going down the wrong rabbit hole. I’ll just set mine at 11FPE and forget it.
Back to practicing
What brand chrono will be used?
And how will it be calibrated?
Doesn’t altitude, temperature, humidity and barometric pressure all affect air density, which can have an impact on speed?
So… there might be different readings when officially testing during the match vs before or after the match…
With WFTC competition, they usually run 4-5 hours long…
Never mind…I’m going down the wrong rabbit hole. I’ll just set mine at 11FPE and forget it.
Back to practicing
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JP, yea could be a bunch of us standing around the chrony station sweating bullets pellets 
Im setting at 10.8 fpe so Im running with that.... and a box full of shims, guides, and an extra spring......
Im setting at 10.8 fpe so Im running with that.... and a box full of shims, guides, and an extra spring......
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I read that Air Chrony is the official chronograph for WFTF, but it doesn't matter, because whatever is used measures your official velocity at the time of testing.
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I agree. I originally asked as I had one errant shot that jumped up 20fps and broke the 12fpe threshold. The other 10 or so shots were 11.5-11.7 fpe. Just wanted to know how this would be handled. Whatever chrono they use doesn’t really matter. Once I get there I can fix the issue in seconds if there is a problem.
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But it COULD matter for certain...
I set up 2 rifles to be under the limit by a reasonable amount with my LabRadar... The owner of one takes his home and measured it with an FxRadar unit that put him over the limit. Someone flying in from another country with a rifle that's difficult to change could be disqualified if the test unit isn't ACCURATE. When we're playing at home, consistency is the most important, but when there's a hard limit, the test unit needs to be ACCURATE ...
I set up 2 rifles to be under the limit by a reasonable amount with my LabRadar... The owner of one takes his home and measured it with an FxRadar unit that put him over the limit. Someone flying in from another country with a rifle that's difficult to change could be disqualified if the test unit isn't ACCURATE. When we're playing at home, consistency is the most important, but when there's a hard limit, the test unit needs to be ACCURATE ...
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What matters is that the shooter is able to adjust their rifle to achieve less than 12fpe using the official chorongraph at the event. Whether it is "accurate" compared to other chronographs or not doesn't matter in this instance, because those other chronographs aren't the "official" device. FWIW, I confirmed that WFTC will be using AirChrony's for their chronographs.
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Hey everyone. The thing to remember is not to get your rifle up to the limit and hope it stays under. It is strongly advised that you are WELL under the limit. Give yourself some wiggle room. Don't run your gear at 11.95 and hope and pray you're safe. It won't work. Set your power low enough so that takes into consideration any variance, whether it's heat, altitude, humiditity. Unexpected things happen. Change your seals and o-rings well before. The burden of responsibility lies with you to make sure your equipment does not cross the line. This is not a rule we are making up to piss you off or be a jerk. It's the World's rules and it's non-negotiable. It's the international standard. It's a hard line. See the rule book on the WFTF site to make sure you're up to snuff on all the rules. This is the NOT the AAFTA rule book, so you don't want surprises.
Cheers.
Garrett
Cheers.
Garrett
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A warning for folks using a radar chronograph, is that these units measure the velocity a few feet/yards out in front of the rifle. Whereas the air chrony measures it right at the muzzle, so there may be a difference between the two, with the Air Chrony being higher. Hopefully at the World's, the chrony won't be as bad as the ones at GPs, which are sometimes not in the ballpark. I have a Nate Chrony on order, hopefully it will arrive before I leave for the World's.
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