Bell shaped power curve

Home Forums AirForce General Chat Bell shaped power curve

Viewing 7 posts - 1 through 7 (of 7 total)
  • Author
    Posts
  • #662
    airtramp
    Participant

    There was a recent question from Benzin on why we want to have a bell shaped power curve which caused me to think about putting the answer in a format that may help others like myself that find it easier to learn with visual signals better than words.

    Following are some cooked up numbers to demonstrate the rational behind a bell shaped curve being better (more shots) than a constantly falling curve. I’m using some assumptions also :

    1. A constant string of 5 shots for each scenario.
    2. Precedent and subsequent shots will vary by 2 fps each.

    Bell Curve . . . Falling Curve

    1) 890 . . . . . . . 920
    2) 892 . . . . . . . 918
    3) 894 . . . . . . . 916
    4) 896 . . . . . . . 914
    5) 898 . . . . . . . 912
    6) 900 . . . . . . . 910
    7) 902 . . . . . . . 910
    8/ 904 . . . . . . . 910
    9) 906 . . . . . . . 910
    10) 908 . . . . . . 910
    11) 910 . . . . . . 908
    12) 910 . . . . . . 906
    13) 910 . . . . . . 904
    14) 910 . . . . . . 902
    15) 910 . . . . . . 900
    16) 908
    17) 906
    18/ 904
    19) 902
    20) 900
    21) 898
    22) 896
    23) 894
    24) 892
    25) 890
    ——————————
    ES = 20 . . . . . . 20

    The constant velocity section is when all the variables of the pcp action are at the optimum.

    You can see that both curves have an extreme spread of 20 fps but the shot counts are quite different.

    Often, a falling curve may not even have a noticeable constant velocity section and if the curve is steep, you will see a POI shift every 5-6 shots if you are shooting anywhere beyond 40-50yd.

    Some well engineered pcp like the Air Arms can get a relatively long constant velocity string (i.e. more than 5 shots) so they will have a useful total shot count of 30-35 within that 20 fps range.

    If the above is all BS, don’t hesitate to let me know. I’m just hoping to help other newbies like myself to get a better grasp of the science of the dark side.

    #27590
    walkonking
    Participant

    Thanks for that post. I dont know how I missed it before.

    Nice work and a good numbers to work with.

    #27600
    y
    Participant

    Thanks for explaining that so well Tramp…

    #27630
    poi
    Participant
    quote AirTramp:

    There was a recent question from Benzin on why we want to have a bell shaped power curve which caused me to think about putting the answer in a format that may help others like myself that find it easier to learn with visual signals better than words.

    Following are some cooked up numbers to demonstrate the rational behind a bell shaped curve being better (more shots) than a constantly falling curve. I’m using some assumptions also :

    1. A constant string of 5 shots for each scenario.
    2. Precedent and subsequent shots will vary by 2 fps each.

    Bell Curve . . . Falling Curve

    1) 890 . . . . . . . 920
    2) 892 . . . . . . . 918
    3) 894 . . . . . . . 916
    4) 896 . . . . . . . 914
    5) 898 . . . . . . . 912
    6) 900 . . . . . . . 910
    7) 902 . . . . . . . 910
    8/ 904 . . . . . . . 910
    9) 906 . . . . . . . 910
    10) 908 . . . . . . 910
    11) 910 . . . . . . 908
    12) 910 . . . . . . 906
    13) 910 . . . . . . 904
    14) 910 . . . . . . 902
    15) 910 . . . . . . 900
    16) 908
    17) 906
    18/ 904
    19) 902
    20) 900
    21) 898
    22) 896
    23) 894
    24) 892
    25) 890
    ——————————
    ES = 20 . . . . . . 20

    The constant velocity section is when all the variables of the pcp action are at the optimum.

    You can see that both curves have an extreme spread of 20 fps but the shot counts are quite different.

    Often, a falling curve may not even have a noticeable constant velocity section and if the curve is steep, you will see a POI shift every 5-6 shots if you are shooting anywhere beyond 40-50yd.

    Some well engineered pcp like the Air Arms can get a relatively long constant velocity string (i.e. more than 5 shots) so they will have a useful total shot count of 30-35 within that 20 fps range.

    If the above is all BS, don’t hesitate to let me know. I’m just hoping to help other newbies like myself to get a better grasp of the science of the dark side.

    I hope you don’t mind if I post this somwhere else as well, with full credit of course. Well said!

    #27640
    airtramp
    Participant

    Hey POI, not at all. The whole idea is to help others so feel free to post anywhere you want.

    #27645
    anthony266
    Keymaster

    Great job Tramp.
    Thank You

    #27654
    bodhisdad
    Participant

    This is the perfect setup, but requires the right balance of hammer weight and valve spring compressive weight. I’m going to mess with this issue this winter as work gets slow. WIll post what i find, definately an advantage to have a slight curve as posted. I’m not far off and just have to try a couple of combinations as well as the time. Its doable and the POI wouldn’t suffer, it will be a fun experiment.

Viewing 7 posts - 1 through 7 (of 7 total)
  • You must be logged in to reply to this topic.