Its an H and A underhammer. Plug is round, sticks out about 5/8", has a taper pin hole cross drilled and a screwdriver slot at rear. Aint comming out with a screw driver! Trying to turn it out with a pin thru the taper pin hole. Trying to shock it loose at the cross pin and tapping with a brass hammer on plug rear.
Tried a long soak in penetrating oil - no luck. Longer soak - no luck.
Tried heating the plug alone then cooling plug and tried to unscrew - no luck. More soak.
Tried heating barrel breech and again no luck.
Soaking again.......Suggestions? Got to be a.better way...