Chrono testing at HFT comps

Discussion in 'Hunter (HFT) & Field Target (FT)' started by skires, Feb 25, 2013.

  1. skires

    skires Well-Known Member

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    Just had a bit of a panic attack ...

    I've just spent a few weeks trying to find a pellet that the old 77 likes and seem to have found some success with a new batch of AA 8.4gr 4.52 Diablo.

    Anyway ... I know that some comps have chrono testing mid course etc and I believe there will be testing at both courses at Kelmarsh at the Worlds.

    So I thought I'd better test the 77 and see if it's ok before it gets too close. So up the garden just with the chrono.

    Now I've noticed with these AA pellets that there is definitely some variation when you thumb the pellets into the barrel. Some go in with a hint of resistance, some seem much tighter and some just fly in with no resistance at all. On a course I tend to shoot off the ones that just fall in. I don't have any scales so haven't weighed them but I've read before that the weights do vary and even pellets under 8gr have been seen in the 8.4gr tins.

    So testing these straight out of the tin up the garden ... the majority of pellets are hovering around 780fps ... which is where I want it ... so that's fine.

    However, I had a couple, that were loose when loading, and these flew through at around 800fps and that's just too close, especially if there is some difference with the chrono. I'm certain that if these were weighed they would be very light and still well under 12fp.

    So, on a course, when the gun goes over the chrono ... do they just use the pellets that you are using? If so, do they put a few through and accept that the odd reading may be a dodgy pellet ... or is it 1 pellet reads 1fps over and you are thrown off?

    I really don't want to have to strip this again and start reducing average power down to 11 or less to accomodate the odd dodgy pellet that is well below weight.

    What's the story please?
     
  2. BOMBER

    BOMBER Little French Maid

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    On the chrono stand you will use your own pellet and get 3 shots if needed but if your first shot is legal then there is no requierment to take another. If you are not legal after 3 shots then you would be asked by the chief marshall to leave the course.
     
  3. skires

    skires Well-Known Member

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    That's that sorted then. Should be no probs.

    Many thanks for the reply.
     
  4. Dave Ramshead

    Dave Ramshead England HFT Team squatter

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    Location:
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    Rivington Riflemen
    Hello Col, if you are now "biccing" won't this find the slack fast ones - just don't use them for the comp / chrono.
     
  5. skires

    skires Well-Known Member

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    Hi Dave

    Yes I can try that thanks.
     
  6. Conor

    Conor Never been banned from sales Staff Member

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    Location:
    Ardboe, Co.Tyrone.
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    Back Hill Ballistics
    The single most useful tool I have seen in use at the chrono station in conjunction with the chrono is a set of SCALES.
    You hand marshal a pellet from your pouch, he/she weighs in front of you then you chrono the gun using the pellet and the power is calculated accordingly.
    SIMPLE and highly effective avoiding argument and embarrassment.

    After all, a 10.2grn doing 805fps is an entirely different ball game than a 7.9grn at the same speed! ;)
     
  7. skires

    skires Well-Known Member

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    Technically you are right. I suppose there is always the chance that someone will be using 10.6gr pellets at 810fps and saying they are 7.9gr ... and weighing would sort that out.

    I was more thinking of slight differences in pellets.

    I shot loads over the chrono yesterday that were supposed to be 8.4gr. The readings were all around 780 fps which is 11.49 fp which is fine. The odd one ... and I mean very very few ... shot near 800 and 1 shot 804. If that was 8.4 gr then that's 12.06 fp. I'm certain it would have been more like 8.2 or even less as it was very slack in the barrel. So at 8.2gr it would have been 11.77 fp.

    So ok your weighing would have sorted that ... but weighing pellets outside in wind ... that will probably give problems at those weights. Also ... at something like the Worlds with 350 shooters going through Chronos over 2 days. You don't want to hold up shooting more than a minimum ... so a quick flirt over the chrono is probably all that is possible. If 1 pellet goes over at 12.06 and the next 1 goes over at 11.5 then no problem. If 3 go over at 13 fp then that's a problem.

    I'll put mine over the local club chrono as well just to make sure my chrono isn't reading low.
     

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