Are these guns box locks or side locks? The reason I ask I just acquired a Zabala Derby 12 ga. with ejectors, very hard to open with both barrels fired. The few theories I have are 1. this gun has a coil spring for the hammers, 2. when fired, and opened, the cocking rods are not only cocking the hammers but also act in the operation of the ejectors.
I have not taken the fore iron off and looked at the type of springs there, but when I tried the ejectors out in the store, they gave me the Zoom ones made out of aluminium and they threw them pretty far, so I guess the springs there are stout also.
It is possible that your guns have different springs types, and could be the reason.
