Not having seen your rifle or being acquainted with it...
Rifle barrels were generally secured with pins or keys (wedges). Additionally, if it isn't a hook breech (tang is separate and the barrel plug has a hook that secures the barrel to the hook breech), then the tang screw needs to be removed. On old guns the lock screw was drilled through the tang so it needs to be removed in order to take the barrel off.
After using a punch to drift the pins or keys out and removing any relevant screws, do not "lift" the barrel from the stock. On those long, skinny stocks you can crack it if it is a tight fit. Rather, flip the gun upside down and gently tap the heel of the buttplate against the ground (preferably a carpeted surface). This induces the barrel to "drop" from the stock and you catch it with your free hand.
Master Gunsmith Wallace Gusler (ret.), late of Colonial Williamsburg, showed me a historical rifle in which neither pins or keys were visible. One removed the pipes which allowed the hidden lugs to disengage from the pins and then the barrel was slid off. Rather clever of the gunmaker. More common are the hidden patch box release buttons. Some were disguised as part of the hinge. Others were disguised as screws.
