Ballard rifling?

[SteelyDan]

I don't really understand how Ballard rifling differs from conventional rifling, and what that means for shooting lead vs. copper-coated bullets. Any help would be appreciated.

 

[mete]

The Marlin website has a forum that goes into this in detail. Their microgroove rifling was critisized for not being accurate with lead bullets .The micrgroove has more grooves but they are shallower.They can be just as accurate but the bullet hardness and diameter are more critical. The ballard rifling is deeper though has fewer grooves and is less critical as far as diameter and hardness of the bullet. These are just two of many types of rifling that have been developed.

 

[Jim Watson]

Modern Marlin Ballard rifling IS conventional rifling; six grooves, probably .004" deep or thereabouts. Contrasted to the UNconventional Marlin Microgroove rifling with 12 to 20 grooves maybe .002" or .003" deep.

I have not been able to find dimensions for REAL Brown or Marlin Ballard rifling of the 19th century. But according to Roberts and Waters, even then it was deeper cut than Sharps rifling and better suited for "grooved" bullets than Sharps which were usually, though not always, loaded with paper patched bullets.