Hi everybody. First post here but it seems like a great forum.
I thought these illustrations might help those trying to tune their m-rod for the first time. The initial settings were guessed at from previous threads here and elsewhere shooting for a 850 FPS string for the 15.9 gr JSB. The notation is P = port turns out from full in (gentle on that one), S = hammer spring turns in from full out, H = hammer stroke turns in from full out. I'm not sure why there was so much variation at high PSI in the first tune but assume that was due to adjusting three points and it needing to settle? Sorry I missed the velocity for two shots in the final string. I'll try to get some new groups when it is calm and post them up here. The gun was doing very good groups before (best 3/16" ctc at 30 meters measured) but POI was varying across PSI. With this more consistent velocity and removing the barrel ring (which seemed to touch the bottom somewhere no matter what) I hope that is all cured. I also did the free trigger mod using the correct delrin spacer from Crossman. PSI is as best as I could estimate (only really accurate across large spans).
Final String:
2890 841
2870 855
2850 851
2830 857
2810 857
2790 859
2770 863
2750 860
2720 860
2690 859
2670 862
2640 863
2610 859
2600 861
2590 858
2570 859
2540 857
2510 854
2480 852
2460 849
2440
2420
2400 844
2390 841
2370 840
