My Long Range Field Grade has the following bore dimensions:
-Left Barrel: Bore .728 Start of Choke from Muzzle 3.5” Length of Choke 2.75” End of Choke from Muzzle .75” Choke Constriction .040” Choke Measurement .688”
-Right Barrel: Bore .728 Start of Choke from Muzzle 3.25” Length of Choke 3.25” End of Choke from Muzzle .0” Choke Constriction .040” Choke Measurement .688”
I was curious of my other Elsie’s so I measured them and found the following:
Specialty Grade 28” Barrels
-Left Barrel: Bore .731 Start of Choke from Muzzle 4.5” Length of Choke 4.25” End of Choke from Muzzle .25” Choke Constriction .042” Choke Measurement .689”
-Right Barrel: Bore .732 Start of Choke from Muzzle 4.375” Length of Choke 4.00” End of Choke from Muzzle .375” Choke Constriction .043” Choke Measurement .689”
Field Grade 30” Barrels
-Left Barrel: Bore .736 Start of Choke from Muzzle 3.5” Length of Choke 3.5” End of Choke from Muzzle .0” Choke Constriction .050” Choke Measurement .686”
-Right Barrel: Bore .741 Start of Choke from Muzzle 3.25” Length of Choke 3.25” End of Choke from Muzzle .0” Choke Constriction .031” Choke Measurement .710”
Field Grade 26” Barrels (Marlin Era, Made in 1946 I believe)
-Left Barrel: Bore .728 Start of Choke from Muzzle 2.75” Length of Choke 2.75” End of Choke from Muzzle .0 ” Choke Constriction .025” Choke Measurement .703”
-Right Barrel: Bore .727 Start of Choke from Muzzle 2.75” Length of Choke 2.75” End of Choke from Muzzle .0” Choke Constriction .009” Choke Measurement .714”
It seems the Long Range and Specialty Grade have a parallel section between the chokes and muzzles. The standard Field Grades do not.