Marauder Shot String Guidance

[1_OF_1]

Hello,

I am learning the ropes of my stock Marauder .25cal. I did two, thirty-two shot strings, which resulted in the following. My questions are:

• How is this performance for a stock Marauder? It seems consistent, however I am still learning.
• Am I right in my thinking about shot string percentage according to max FPS?
• What PSI should I be shooting between? How do I figure this out? Do I fill the rifle to 3000psi then shoot 9 shots and check my PSI, which would then be my starting point? Do the same with end point?
• Any other points or guidance welcome.

Pellet: JSB Exact King .25cal, 25.4g

PSI: 3000 - 2100

PSI Per Shot: 25psi

Max. FPS: 815

Shot String 1: 25 shots within 2% of max FPS, 32 shots within 4% of max FPS.

Shot String 2: 31 shots within 2% of max FPS, 32 shots within 4% of max FPS.

 

[Yo]

Man that's pretty awesome straight out of the box unregulated! I'd just leave it alone and just fill to 3000psi to start. I wouldn't tinker with it one bit based on what you just showed. YO!

 

[ackuric]

Your tune is typical of a stock marauder at its power level, I would leave it and shoot it at the 3k-2.1k range that you have been. You could go down the rabbit hole but thats up to you! According to my sheet you're around 12% down from your plateau, which would explain the higher shot count / great efficiency with a stock marauder. From what I recall, with the stock marauder, 52~ fpe peak sounds abouut right which is what my spreadsheet predicts midway through your psi range.

Stock Marauder
Date: Temp: 60
Chronograph distance: 0ft
Loss from Chrono Distance: 0 fps
Chrono Loss Added: Yes

Projectile Mass: 25.4 - Ratio to Air: 71.5% / 28.5%
Psi Start: 3000 - Psi End: 2100 - Airuse: 900 psi
Psi / Shot: 28.1 - CC / Shot: 2.12 - Fpe / Psi: 1.31
Res Vol: 190cc - Reg Vol: 0cc - Setpoint: 0psi
Shots On Reg: 0 - Shots Off Reg: 32 - Total Shots: 32

Efficiency: 1.63 fpe/ci
Valve Close @: 9%

ES: 18 fps ( 2.21%) - Std Dev: 4

Total Energy: 1175 - Fpe Per in/Barrel: 1.92

Total Shots < 1% ES: [23/32] best streak: [11] shots [#10-20]

Fps/Fpe High Fps/Fpe Avg Fps/Fpe Low
815 - 37 807 - 37 797 - 36

(1-10) 801 - 805 - 806 - 811 - 801 - 807 - 803 - 802 - 797 - 806
(11-20) 804 - 808 - 807 - 806 - 812 - 808 - 806 - 811 - 810 - 807
(21-30) 815 - 812 - 803 - 815 - 811 - 808 - 809 - 807 - 809 - 805
(31-32) 807 - 800
Most repeated: [807] Duplicates: [5]



For comparison here is a string from my marauder shooting 33.95's.



Marauder
Date: Temp: 60
Chronograph distance: 0ft
Loss from Chrono Distance: 0 fps
Chrono Loss Added: Yes

Projectile Mass: 33.95 - Ratio to Air: 71.5% / 28.5%
Psi Start: 3100 - Psi End: 1700 - Airuse: 1400 psi
Psi / Shot: 46.7/167.3 - CC / Shot: 5.04 - Fpe / Psi: 0.34
Res Vol: 190cc - Reg Vol: 53cc - Setpoint: 1925psi
Shots On Reg: 25 - Shots Off Reg: 5 - Total Shots: 30

Efficiency: 1.45 fpe/ci
Valve Close @: 29%

ES: 19 fps ( 2.16%) - Std Dev: 4

Total Energy: 1709 - Fpe Per in/Barrel: 2.99

Total Shots < 1% ES: [22/30] best streak: [10] shots [#12-21]

Fps/Fpe High Fps/Fpe Avg Fps/Fpe Low
879 - 58 869 - 57 860 - 56

(1-10) 877 - 872 - 872 - 866 - 873 - 875 - 879 - 868 - 873 - 868
(11-20) 877 - 865 - 869 - 868 - 870 - 864 - 866 - 868 - 869 - 870
(21-30) 863 - 872 - 867 - 864 - 868 - 868 - 872 - 868 - 865 - 860

Most repeated: [868] Duplicates: [7]

 

[brian_null]

Dude! Seriously... spread the love of that spreadsheet! It's freaking awesome!

 

[1_OF_1]

Great feedback. Thank you for the guidance.

 

[biohazardman]

Seeing that you have to shoot 9 shots to get to your starting point you can fill to whatever that starting point is and not have to shoot the 9 shots.

 

[1_OF_1]

Yup, that is what I was wondering. Thanks for the feedback.