first question fior me would be why was it loaded for yrs??
any how, MY suggestion is call a good gun smith and have them safely remove thinsg for you
as after all the time that passed, not knowing how gun was stored, the powder can have gone bad for sure
and NO one here can tell you if its good or not, not knowing 100% of details on how it was store the entire time!
SOP< for safety reason, Contact a smith, let him know the issue and have them handle it for you safely!