Regulated custom shop marauder tuning?

[redtrucker610]

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

[Motorhead]

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 

Scott

[redtrucker610]

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.

[Motorhead]

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.