Tune for more power

[caniborrowsomeammo]

OK, I got me a new SynRod. Only have Benji Domes for now. Kings and H&N Hunters ordered but not shipped with gun.
Haven't touched anything yet on gun.
Shot some strings yesterday:
Temp 85Deg.------>3000+ psi on gun gauge. 3000 psi on McMaster Carr pump gauge. Gun gauge used as constant.
739 750 752 756 756 760 764 763 770 768 772 768 775 768 777 781 2600 psi end . Avg 763 FPE 35.95

2600 psi---
784 788 782 784 783 786 789 780 784 780 782 781 770 773 769 764 2300 psi end. Avg. 779 FPE 39.5

This morning 59 Deg.----------2750 psi start. 764 764 768 767 769 771 770 775 541? 779 785 778 789 778 779 778 2300 psi end. Ave 662 (774 without the 541)
FPE 27 (37 without the 541)
Groups around 1" without flyers @ 40 yards, but only scope I had available is Leopold VXI 1x4 Heavy Duplex. New scope will be here W/ ammo.

OK what are your suggestions? I don't need a high shot count. 8 would be fine. But would like high FPE.

[hill]

OK, I got me a new SynRod. Only have Benji Domes for now. Kings and H&N Hunters ordered but not shipped with gun.
Haven't touched anything yet on gun.
Shot some strings yesterday:
Temp 85Deg.------>3000+ psi on gun gauge. 3000 psi on McMaster Carr pump gauge. Gun gauge used as constant.
739 750 752 756 756 760 764 763 770 768 772 768 775 768 777 781 2600 psi end . Avg 763 FPE 35.95

2600 psi---
784 788 782 784 783 786 789 780 784 780 782 781 770 773 769 764 2300 psi end. Avg. 779 FPE 39.5

This morning 59 Deg.----------2750 psi start. 764 764 768 767 769 771 770 775 541? 779 785 778 789 778 779 778 2300 psi end. Ave 662 (774 without the 541)
FPE 27 (37 without the 541)
Groups around 1" without flyers @ 40 yards, but only scope I had available is Leopold VXI 1x4 Heavy Duplex. New scope will be here W/ ammo.

OK what are your suggestions? I don't need a high shot count. 8 would be fine. But would like high FPE.

More power =

Start by turning the Velocity Screw (5/64" wrench) CW untill stops - then turn CCW 5.5 turns ( remember to remove the set screw first ).

Fill to 3000 psi and chrony a string.

[caniborrowsomeammo]

Factory was 3 3/8 CCW Now 5.5 CCW. Was very careful to only snug jam screw and not move setting.

3000 on pump is now 3200 on gun. Was 3000 Pump 3000+ Gun yesterday. Oh well, I have a spare McM C gauge.
84 deg. 3200 psi: 754 761 762 762 770 770 774 787 Avg 767 FPE 36.3 3000 psi 776 776 774 778 782 780 786 787 Avg 779 FPE 37.4 2750 psi .
Shot another string from this fill 784 784 788 789 789 792 789 794 Avg 788 FPE 38.3 2475 psi .
So I see I'm not getting the advantage of a 3000 psi fill. And not getting the FPE I was getting yesterday.

HS and HT next I assume.

[hill]

Fill to the same pressure, then turn the Hammer Spring (1/4" wrench) fully CCW - then turn it 5 turns CW.

Shoot a 10 shot string and post.


Tim

[caniborrowsomeammo]

Tim, appreciate all this!!!!!!!

Here goes
Temp 91 deg. HS 5 turns CW (factory @ 4 CW)

3175-3200 psi : 764 764 766 773 775 (3075 psi) 777 776 787 787 792 3000 psi Avg. 776 FPE 37.2

[hill]

Tim, appreciate all this!!!!!!!

Here goes
Temp 91 deg. HS 5 turns CW (factory @ 4 CW)

3175-3200 psi : 764 764 766 773 775 (3075 psi) 777 776 787 787 792 3000 psi Avg. 776 FPE 37.2

To tune a Marauder Rifle some charge as much as $125.00 ( + shipping ) - but I do it for free…. because I like this hobby ( pellet guns ) ( since 1972 { I'm not that old lol } ).
You're very welcome


Ok, that being said………… something is wrong
Is your barrel to bolt O-ring in place ? ( pic )

[caniborrowsomeammo]

Yes it's there.

[hill]

Ok then….


The velocity screw is at 5.5

Set hammer throw (1/8" wrench) at - fully CCW (0)

Set hammer spring (1/4" wrench) at - fully CCW then 6 CW


This should be at/near full power.



Lets see what happens ?

[PB_Matrix]

Posting just to watch this thread, have similar results, then added 12 pound spring which brought the FPS up to 820 more or less.

[caniborrowsomeammo]

I can live with this, should get a curve in here if I kept shooting 2 full mags. The first shot sounded like some hammer bounce, the rest didn't.

The HT was @ 2 5/8 CW, now at 0.

91 deg. 3200 psi: 813 832 831 831 840 3075 psi 833 839 839 840 841 2900 psi Ave 833 FPE 42.8

That got me an extra 3 FPE, that will help @ 40-50 yards.

Tim you are the best.