I just shot both pellets today. My regulator is set at 130 bar, the hammer spring adjustment is measured at 16.65 mm and the hammer stop is measured at 8.3 mm.
The JSB 25.39 gr Jumbo Monsters MK I version were at about 880 fps with the power wheel set at max and 860 fps with the power wheel set on 5.
The JSB 25.39 gr Jumbo Monsters MK II version were at about 890 fps with the power wheel set at max and 865 fps with the power wheel set on 5.
The JSB 18.13 gr pellets were at about 1025 fps with the power wheel set at max, about 1010 fps with the power wheel set on 5, about 975 fps with the power wheel set on 4, about 915 fps with the power wheel set on 3, about 860 fps with the power wheel set on 2 and about 810 fps with the power wheel set on 1.
The Air Arms 16 gr. pellets were at about 1055 fps with the power wheel set at max, about 1050 fps with the power wheel set on 5, about 1020 fps with the power wheel set on 4, about 960 fps with the power wheel set on 3, about 910 fps with the power wheel set on 2 and about 860 fps with the power wheel set on 1.
What I found interesting was that the 16 and 18 grain pellets were almost as accurate at Max power as they were at lower power settings. The worst accuracy for both pellets in my rifle was power wheel setting 5 and it was just over dime sized groups at 30 yards.
