a used Marlin 336 30-30 Winchester Rifle. The barrel length on this Rifle is 20". This work horse Marlin 336 was made in the famous North Haven Connecticut facility in 1981. This 336 has the highly desirable JM stamp on the barrel near the receiver, showing this is the original JM or John Marlin proof mark. Rifling looks great and barely used. There is some bluing scuffing on the magazine tube and two spots on the barrel.