To remove the cylinder on mine I need to remove a very small screw and knock out the wedge that holds the barrel. Losing the small screw would render the gun unusable. This procedure applies to many muzzleloading revolvers.
Some pistols are made so the cylinder can be removed easily, which sounds like the type you have.
I agree that loading all six chambers at the same time with the same pressure applied to the ball/load would aid accuracy.