Gun grease and BP don't play very well together. I use Bore Butter to lube my arbors (thats the post thingy) and they never fail to come apart easily, even after 60+ rounds.
Use a little balistol & water to dissolve the crud thats keeping you from taking it apart.
Fingers (Show Me MO smoke) McGee - AKA Man of Many Colts - Alter ego of Diabolical Ken; SASS Regulator 28564-L-TG; Rangemaster and stage writer extraordinaire; Frontiersman, Pistoleer, NRA Endowment Life, NMLRA, SAF, CCRKBA, STORM 327, SV115; Charter member, Central Ozarks Western Shooters
Cynic: A blackguard whose faulty vision see things as they are, not as they should be. Ambrose Bierce