M-Rod Tuning

[GadgetX]

Thank you sir !!

I shot 200 pellets through the chrony today.  Stoke made a difference, best when al the way ccw..  preload made a difference, best when it was ~ 6-6 1/2 turns.  But the metering valve only made a difference if it was completely shut to off cw.  No change from 2 - 4.5 turns.  Going to find someone to setup the gun.  I obviously don't have a clue.  The best FPS was 829 FPS.  Same as the factory settings.

Mike

[GadgetX]

Ok ended on the H=6.5 S=.25 V=4.25.  I have 40 shots (5 clips) from 3000 psi, JSB exact 25.4 gr.  Lowest FPS 742, highest 858.  I have 2200 psi left.  Not exactly what I wanted (800-900 FPS), but I think I could shot 60-70 shots.  BTW - all shots were .7" at 30 yards.  I actually ruined my back stop made of 2x4 treated.  Come on Mr Beaver !!

Mike

[GadgetX]

Seems everyone has a heavier # 10 spring.  I suspect that spring will help at higher psi (2500-3200).  Does that hurt at lower psi (1500-2300)?  Is it a basic mod that a journeyman can do or is it a pro gunsmith mod?  Would still like the bulk of shots to be 850-900 fps with JSB Exact 25gr pellets on the mrod.  I can live with 25 shots.  Now I am getting 40+ shots.

Mike

[aack73]

the heavier spring will help you achieve the higher velocities at higher fill pressure. if your happy with what you got, then i would leave it be.

  changing that spring out is pretty simple. in my opinion the entire gun is pretty simple to disassemble and work on. if you have enough mechanical skills to disassemble it, you should be able to put it back together just fine. print out the diagram and pay attention when taking it apart.

[GadgetX]

thanks, Im thinking about a new spring...

Mike