GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: redtrucker610 on May 16, 2018, 09:43:44 AM
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I picked up a custom shop .22 caliber regulated marauder a few weeks back. I got a chance to shoot it over a chronograph this week. It seems to be shooting a little slow. It averaged 774 FPS with crosman hollow point pellets over 65 shots from 3000 down to 1600. I recorded the stock settings so I had a base line. The velocity screw was at 4 turns out. The hammer spring was at 5 turns clockwise and hammer throw was at 8 turns counter clockwise. I tried to adjust the speed up a little but nothing changed. I opened the velocity screw to 4.5 turns out. I turned the hammer spring in a turn and the hammer throw out a turn twice for total of 10 out. I was able to adjust the speed down to 630 fps by adjusting throw in 2 turns from the stock settings. I know its regulated but I thought there should be some ajustability. For now I have turned everything back to the stock settings except the velocity screw. The manual is no help as its for the standard marauder. Any suggestions on tuning? I posted the shot string in another thread but will post it again here.
Shot 1 794
Shot 2 779
Shot 3 776
Shot 4 779
Shot 5 774
Shot 6 777
Shot 7 767
Shot 8 774
Shot 9 773
Shot 10 773
Shot 11 786
Shot 12 773
Shot 13 772
Shot 14 772
Shot 15 766
Shot 16 777
Shot 17 774
Shot 18 774
Shot 19 775
Shot 20 775
Shot 21 776
Shot 22 773
Shot 23 775
Shot 24 776
Shot 25 771
Shot 26 772
Shot 27 775
Shot 28 773
Shot 29 775
shot 30 777
shot 31 771
shot 32 777
Shot 33 776
Shot 34 778
shot 35 777
shot 36 774
shot 37 773
shot 38 776
shot 39 773
shot 40 772
Shot 41 781
shot42 778
shot 43 779
shot 44 773
shot 45 777
shot 46 776
shot 47 780
shot 48 777
shot 49 777
shot 50 780
shot 51 777
shot 52 776
shot 53 769
shot 54 778
shot 55 772
shot 56 773
shot 57 775
shot 58 775
shot 59 772
shot 60 769
shot 61 775
shot 62 773
shot 63 774
shot 64 774
shot 65 771
shot 66 764
shot 67 767
shot 68 755
shot 69 758
shot 70 756
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I will make an assumption NO ONE has any of the inner details of the valve being used, its poppet spring strength, available plenum volume, hammer weight or transfer size valve to barrel etc ...
Which makes recommending what to do next a WAG ( wild azz guess )
I will state that w/o changing reg set point or anything else internal for you & us to get a clue on the stock guns potential taking the settings you can fool with to max and see whats there ???
Transfer restriction ( If still used ? ) out from seated 5 turns
Hammer stroke at max ( CCW on 1/8" screw all the way )
Hammer spring tension ( CW on the 1/4" screw "Up to" @ 18 turns or so ) * This the primary screw that will raise the power until it peaks
Let us know what you find out & we can go from there .... Your our Ginnie pig / Lab rat sorry to say :o
Scott
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Scott thanks for the reply. Just my luck, a Marauder rookie and a Ginnie pig. Do have some questions though. I know you know your way around these things. The transfer restriction screw, You mention 5 turns out for maximum. The manual states 4 1/2 being maximum. So I take it I could back it out another 1/2 turn? The hammer spring preload, the manual states 6 turns max, you stated 18. I only went one extra turn in when I tried adjusting it. Should I have seen an increase with just one turn on the hammer spring? I take it I actually have more room to work with? I wonder if I make adjustments looking for some extra FSP and just end up using more air with out gaining anything because of the regulator? I really don't need the extra speed. I only use it for backyard fun. It just seems to be shooting slow compared to what Crosman has it rated at.
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Scott thanks for the reply. Just my luck, a Marauder rookie and a Ginnie pig. Do have some questions though. I know you know your way around these things. The transfer restriction screw, You mention 5 turns out for maximum. The manual states 4 1/2 being maximum. So I take it I could back it out another 1/2 turn? The hammer spring preload, the manual states 6 turns max, you stated 18. I only went one extra turn in when I tried adjusting it. Should I have seen an increase with just one turn on the hammer spring? I take it I actually have more room to work with? I wonder if I make adjustments looking for some extra FSP and just end up using more air with out gaining anything because of the regulator? I really don't need the extra speed. I only use it for backyard fun. It just seems to be shooting slow compared to what Crosman has it rated at.
5 being SAFELY out of the way and not in effect ...
Hammer STROKE has about 18 turns ( That is if there still using a conventional M-rod hammer ) None of us know ???
Yes ... generally more speed / power requires more air which equals less shots per fill.