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Thread: shot to shot consistency (springers)

  1. #1
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    Default shot to shot consistency (springers)

    so, there i was, about 90 min, before the usual grand prix/braai....... the sun was out, i thought it was a good opportunity to get the chrony out and get some "real readings". on a "typical" hunting outing, i rarely take more than 15-20 shots (5 or so to check/reset zero, rest on quarrys).............so i figured i would take 5 consecutive shots, and the remaining 10 before the warm-up lap, in random intervals.

    here's the result:

    diana model 46, model 35/50 main spring, light piston polish, little moly on spring/guide/piston-side.....etc using bisley magnum 4.51mm 10.6gr

    1 761.7
    2 767.8
    3 757.1
    4 744.0
    5 749.1
    6 745.7
    7 768.3
    8 747.0
    9 763.4
    10 761.0
    11 758.0
    12 760.8
    13 756.4
    14 749.6
    15 758.8

    std. deviation: 7.8 fps
    spread: 24.3 fps

    i've ordered the ultra tuning kit from chambers, and hopefully it will improve the velocity variations........will keep you posted.

    just wondering.....how do these figures compare to "tuned-out-the-box" springers like the prosport/tx200 ????



  2. #2
    Marksman
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    Hi Urabus
    You should avoid using 10.5gr pellets in a .177 springer.
    It puts a lot of strain on the spring and guide...there have been a lot of discussions on this on international forums. Eventually the spring will fail.
    Also you will find that springers put out more power with lighter pellets [unlike PCPs]
    Best weight would be in the 8 to 8.5gr range, AA fields or Crosman Accupels.
    Best tuning kits bar none are the ones from James Maccari in the US but they are a little expensive.
    I tuned my AA ProSPort and it is now so smooth and accurate it defies description.
    Shoots AA fields at 840fps with an ES 0f 10fps...no twang and an absolutely smooth firing cycle.
    The secret is in the tight spring\guide tolerances and the thick gooey spring tar he sells with the kits.
    Absolute power is not everything...especially in springers.
    Call me if u need any more info
    Guido www.delgi.com

  3. #3
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    Quote Originally Posted by guido
    Hi Urabus
    You should avoid using 10.5gr pellets in a .177 springer.
    It puts a lot ...............Eventually the spring will fail.
    yeah, i know. it's just that my springer performs better with heavy pellets such as bisley magnums, crosman premiers (10.5 gr)......etc. according to JM, this is very common to diana springers due to "design flaw" (compression chamber too big, piston seal too small) hence, i consider the main spring as a "wear and tear" item. btw, do you know if bisley magnums and h&n baracudas are the same???? they sure look the same. however, i can't get nice groupings with the baracudas (perhaps 4.51mm vs 4.5mm?)

    Quote Originally Posted by guido
    Best tuning kits bar none are the ones from James Maccari in the US but they are a little expensive.
    I considered the GSI kit, but i was also looking to get other accessories as well, so i thought i would get them all in one go from chambers........i will wait and see how the ultra tuning kit performs, and maybe go for the GSI kit in the future (when the main spring fails)

    Quote Originally Posted by guido
    I tuned my AA ProSPort and it is now so smooth and accurate................. and the thick gooey spring tar he sells with the kits.
    from what i've read, the prosport is pretty much the best springer "out the box" in the world. i can only imagine how smooth/consistent, a tuned example such as yours, is. is yours a 12 ftlbs uk or the 15.5 ftlbs "fac" version? how would you rate the prosport vs tx200 mkiii/hc (same action?)???
    also, i've only got some moly lube on the spring......i'm keen to try open gear/chain wax.......any experience? or would you say velocity tar is the way to go?


    Quote Originally Posted by guido
    Absolute power is not everything...especially in springers.
    fully agreed, especially with diana model 46. due to the fore-mentioned "design flaw", and the excessively long transfer port (part of the loading breech), it lacks (big time) the power tuning potential of say.....an HW80. all i'm after is smooth fire-cycle, short locking time and consistency/accyracy.

    thanks

  4. #4
    Marksman
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    Bisley Magnums are identical to Barracudas...the batch you have may be a different head size though.
    Biz mags are not sorted bt head size as are the standard Barracudas.
    Barracuda Match is sorted.
    My Pro Sport is a FAV version. When I got it it was pushing about 14.5ft\lbs.
    With the JM kit it now sits at about 13ft\lbs but is even smoother and more accurate.
    Have not really used a TX200 but the Pro SPort just looks so much nicer with the hidden underlever and short shrouded barrel...also the stock has nicer lines especially in the cheekpiece area. As you mentioned both have exactly the same action but the Pro Sport does away with the ratcheting anti bear-trap mechanism which is quite noisy.
    Velocity tar is the tried and tested component...I have no exerience with other lube\dampers.
    Cheers

  5. #5
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    thanks...........

    hmmm prosport....i like
    did you see the custom ones they got at BAR (airgunbuyer.com)?????
    nice wanut stock, carbon fiber barrel shroud/silencer, stainless steel bits.........


  6. #6
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    oops double post..........
    <span class='smallblacktext'>[ Edited Tue Jul 27 2004, 02:11PM ]</span>

  7. #7
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    hi all again, you guys must think i've got too much time on my hands.................well what can i say????? i'm one of those obessesive nuts........once i get into something, i eat/drink/sleep that particular something. sad!!!! i know, i guess there's a thin line between being passionate and crazy.........

    anyways, as guido brought up the subject of sorted (premiers/match..etc) and unsorted pellets, i thought i would run a mini-experiment.

    i basically ran the same test as on sunday. keeping everything the same (factors like humidity, temp, light intensity...etc were out of my control though...) and crosman premiers (10.5gr) were used.

    result:

    1 725.9
    2 732.7
    3 729.7
    4 728.9
    5 725.7
    6 734.3
    7 735.3
    8 735.5
    9 730.2
    10 726.2
    11 732.3
    12 737.2
    13 737.4
    14 734.7
    15 731.5

    spread: 11.7 fps
    std. deviation: 3.97 fps

    hmmm.......the spread/std. deviation was reduced by more/just less than 50%. i guess the premium we pay for them is well justified. when i get the hornet, i will run run more tests, the variation in power delivery "should" be eliminated by the regulator, and hece produce a more conclusive result...........

  8. #8
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    "the variation in power delivery "should" be eliminated by the regulator"
    Sorry but you're in for a surprise. Shot to shot deviation of about 3 fps is about the norm and is seen as acceptable for a regulated gun. Let me know about your tests aswell, would love to know.
    Not too sure what the extreme spread will be like over let's say 40 shots. I saw a review on the Hornet which had a extreme spread of about 40 ft with about 50 shots but can't remember where I saw it. If I find it I'll post the link.
    I'm buying a TX200 next week and will then test (in std format - 16ft) and let you know.
    <span class='smallblacktext'>[ Edited Wed Jul 28 2004, 09:34AM ]</span>

  9. #9
    Marksman
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    Hi Guys
    In my experience an ES of 3fps is very unlikely with a regulated gun.
    First of all chronos are not that accurate...they give a tolerance of about 2% and more especially if the distance between the 2 sensors is very short as on the Chronys and such. Oehlers are more accurate especially using 3 sensors and spread far apart. The 3rd sensor takes a test\comparative reading.
    Secondly pellet weights vary slightly and will cause velocity differences.
    An ES of 8 to 10fps is more the norm on a regulated gun. My Steyr LG 100 and my NJR100 have an ES of about 8fps with sorted pellets.
    My AA ProSport springer is more like 15fps.
    My AA S200 will give about 50 fairly consistent shots with a power curve incorporating an ES of about 35fps.
    My Talon on full power gives 70 shots with an ES of about 45fps.
    Even 45 fps is not enough to cause concern since the trajectory out to 60 yds is not affected that much.
    I have checked both on the shooting bench and using trajectory software.
    I think too much importance is given to ES.
    On regulated guns it really is irrelevant.

    Just my experience......

  10. #10
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    eeish............40fps over 50 shot.......i might as well save the money and just use my diana. from what i've read, they seemed to perform very well (i thought this was a well-informed review: http://www.reviewcentre.com/review27504.html). maybe it was one of those MK1 examples that suffered teething problems.

    got the TX yet? i see you are putting a hawke varmint 2 on it........are they spring/piston rated? i thought about putting an air max on the HC/ProSport (when/if i get one). this has just opened up more possibilities..................

    cheers

  11. #11
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    Had to cancel the TX for now, budget doesn't allow it right now. It's a Hawke Varmint 1, the 2 only goes up to 6-24, and yes they are spring gun rated.
    Most if not all of their scopes are spring gun rated.
    Nothing wrong with Hawke but I still prefer Nikko.

  12. #12
    Marksman
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    hehe Neil...I see you changed your signature...

  13. #13
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    Jip, doesn't help me listing equipment I don't have anymore ...

  14. #14
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    hmm....NJR 100, heerlik ek se

  15. #15
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    You think that's HEERLIK, you'll see what will be added to my signature in about 3 weeks, then we'll see what's heerlik. Wait till then ...

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