I switch from 250mm 25 cal to 350mm 30 cal last night the 25 shooting at 890 fps was giving me issues cycling so I turned it down to 820 and it ran perfectly I left the same settings with the 30 cal and I'm getting an average of 760 FPS around 55 FPE and over 5 magazines per fill it has more power in it but this is plenty for my needs critters at 20-40 yds This rifle killed a Fox when it was a 25 Cal