Finaly shooting .25 cal - M-Rod is here

[Stefan]

Got it a few days ago, but I wasn't able to try it until today. I cleaned it up before and lubed it (barrel was quite greased).
I weighted 25,4 gn JSB Kings.
My factory settings were (if I'm not wrong) TP 3 turns from closed, and hammer tension and stroke length were at 0(full out).
I used the setting I found here on board - TP 3,5 from closed, Hammer tension 5,25 in from min tension, and Stroke length 1,125 from max stroke (I might be wrong about this last one, I turned it in 1,125 CW).
Here's what I got:
1. 861 - 3000 psi
2. 854,4
3. 857,5
4. 856,9
5. 853,6
6. 855,6
7. 8. - loaded two pellets - 636,4
next clip
9. 843,6
10. 845,1
11. 838,9
12. 837,3
13. 850,3
14. 839,3
15. 839,3
16. 821,9
third clip
17.18.19 - loaded three pellets - 533,9
20. 815,2
21. 815,1
22. 807,4
23. 792
24. 790,7
fourth clip
25. 794,1
26. 779,1
27. 769,5
28. 760,3
29. 747,9
30. 736,6
31. 718,6
32. 712,9 - 1100 psi

I'd like to hear some suggestions. I'm up for balance between power and shot count.
 

[PakProtector]

Well, the first shot is fastest. Also, it isn't all that fast. Let me suggest opening the transfer port needle another turn. Then shoot a clip. If the first shot is still fastest, reduce hammer pre-load so you get the increase-peak-decrease curve to the velocity plot( say, two more clips).
cheers,
Douglas

[Stefan]

I have ordered the regulator in the meantime. I didn't play with hammer setting, I just opened up T/P a half turn. Speeds are around 840 fps with JSB Kings.
I have tinkered with stock - I hate that factory color, and I didn't like the finish on the trigger, so I had it chromed.

the trig






stock


and assembled



groups at 90 meters



zeroed at 50 meters. shooting 4 shots at a target from 3000 psi down. after two clips it gets poi shift


penetration at 50 meters




the looks

[dryanw]

May I ask you what the chroming cost? Thats pretty sweet, and my goal is to have a completely chrome/nickel plated QB 

[Stefan]

It didnt cost me anything, a friend of mine did it. I am thinking about doing mat chrome on bolt handle, and shiny chrome on bolt.

[PakProtector]

Where are you getting the reg?

Also, what do you have planned besides dropping it is?
cheers,
Douglas

[Stefan]

I'm getting the reg from Altaros.cz.
and the second question, I'm not quite sure what you mean?

[PakProtector]

I'm getting the reg from Altaros.cz.
and the second question, I'm not quite sure what you mean?

What goes between the regulator and the end of the valve? a spacer? the gage block? just sliding the reg in against the valve?
cheers,
Douglas

[Bill G]

Reg and .25 Marauder leaves you with very few shots.  Reservoir is just too small to have a reg and a large enough plenum to achieve good power for a .25cal IMO.  You can tune it with the factory settings to shoot ~50fpe for 10 shots with An ES of 10fps or less without the reg.  With a reg you can get the same but you spend exrta $ to do it.  That has been my experience based on a stock rifle.

Bill

[PakProtector]

Is about it Bill... I would like another reg for the next project though, just in case you want to sell...

I suspect you coud make a fine indoor target gun to shoot FTT's at around 30 FPE...but that is mid-level .22 power.
cheers,
Douglas

[Stefan]

Reg will come in tomorrow, than we shall see what is going to happen. It will be set at 140 bar. It goes directly to the valve i think (looks like that on diagram). Gauge will read the real pressure inside cylinder (without venting hole). I'll post the results of course.

[jaytime25]

those are some nice groups at 50 meters

[Stefan]

thanks
reg came in. installed it easy. its set on 2000 psi output. any suggestions how much to open t/p, and how to adjust hammer and stroke length? Or how to start adjusting?
Also I finished the bolt today - chromed also it slides much easier now TBH. And looks bit prettier

[Stefan]

Now, I have installed the regulator.
Starting pressure 3000 psi (in all strings), transfer port 3,5 turns from closed, no preload on hammer spring and hammer stroke
1.786,4
2.758.3
3.755.6
4.789.8
5.756.9
6.758.9
7.756.6
8.763.3

9.765.2
10.771.1
11.762.2
12.763.8
13.- no reading
14.767.1
15.797.6
16.765.4
End pressure 2200 psi


I have altered the setting to transfer port the same, hammer stroke 10 turns in, start at 3000 psi

1.803.1
2.775.7
3.766.7
4.771.9
5.771.9
6.Err
7.761.7
8.765.3
End pressure 2100 psi

Altered setting again to Transfer port 3 from closed,  hammer tension 5 turns,  stroke tension 1 turn. Start at 3000 psi

1.766.2
2.761.1
3.762.2
4.-
5.766.3
6.755.4
7.759.6
8.756.5

2400 psi

9.757.3
10.754.8
11.754.8
12.762.7
13.761.8
14.752.2
15.Err
16.745.2

1900 psi


Transfer port 4 turns out, hammer tension 5,5,  stroke 0,5
1.770.1
2.766.7
3.770.7
4.-
5.793.4
6.770.4
7.767.3
8.-

2200 psi

And finally I used this setting
Transfer port 4, Hammer 3.5,  stroke 1
1.797.1
2.767.1
3.762.4
4.763.1
5.769.0
6.Err
7.761.9
8.762.1
End pressure 2400 psi


In what direction should I go? Should I change the pressure setting on regulator, and on what? t/p etc? any suggestion is quite welcome