I recently purchased a new Leupold Mark 4 with M3 knobs. I just received it in the mail today and everything looks good except when I try to spin the elevation knob. It only goes about a half turn and stops around 31 when raising the elevation. I didn't force it and thought I'd ask before I try more troubleshooting. I'm not familiar with Leupold Mark 4 scopes or anything of that caliber of scope. Any help is appreciated.