It is always better to clean from the breech end. As for using JB - I only use this sparingly. Normally on a new barrel to remove any microscopic burrs and then when accuracy begins to falter. Excessive use of JB can round out the edges of the rifling and cause unrepairable damage. (even the JB container says to use sparingly)
However, Omega is correct so for a ML I would guess you should clean from the muzzle.
Last edited by bronko22000; 07-15-2011 at 04:44 PM.