1 ugly 50 shot string.

[aack73]

marauder .177 factory tuned. only adjusted the trigger and cleaned out the aluminum shavings. I over fill it a little. i've shot it out to 30 yards and it will shoot pellets in to 1 ragged hole if i can hold steady. I was surprised by this shot string. i guess i was expecting some magical just worked itself out tune   . i even get good groups and barely low poi out of the last 10 shots too. almost afraid to tune it cause it does shoot pretty good.(at least by my standard)
crosman premier heavies
  Starting psi 3100
1.   918     26.   861
2.   921     27.   855
3.   918     28.   848
4.   919     29.   846
5.   915     30.   846
6.   915     31.   839
7.   911     32.   839
8.   912     33.   838
9.   908     34.   830
10. 908     35.   825
11. 901     36.   820
12. 901     37.   823
13. 899     38.   816
14. 892     39.   810
15. 891     40.   808
16. 889     41.   ----
17. 884     42.   799
18. 884     43.   791
19. 885     44.   783
20. 879     45.   781
21. 876     46.   777
22. 872     47.   771
23. 868     48.   766
24. 867     49.   759
25. 861     50.   755
 
    End psi 1600

[rsterne]

You have too much hammer spring tension and/or hammer travel.... There is NO bell curve, the fastest shots are at the highest pressure.... Reduce the hammer strike, and you will lose velocity, but get a much flatter shot string.... If more velocity is required, you may have some room left to increase the transfer port opening ("velocity adjuster")....

Bob

[Markez]

That looks the same as mine. It was set at hammer spring tention 4 turns in cw and I took
1/2 turn out ccw( 1/4 in. allen wrench ) and now I have a nice curve. I was afraid to touch
mine at first but once I started I couldnt stop.

[JonnyReb]

 Amazingly accurate and quiet rifles. Congrats on yours., J