I have a Jeffery marked 'the Jungle Gun'. The rifling appears to be full lenght of the barrel, almost like raised pitting with a gentle twist. Unfortunately I have yet been able to shoot the gun as the barrels are in good condition, the rest of the gun is in poor condition- stock damaged, and top strap broken at the safety. If is one of my 'project' guns for this year.
Regards,
Charl