The "improved" mod 6 did have a cast receiver, but none of the parts will interchange. Makes one wonder why Remington didn't just give it a different number.
I've only seen one "improved " mod 6, and that's been a few years ago -you know what I mean. It was a much heavier receiver, and if not cast, gave me that impression.
Frank DeHaas' book, "Single Shot Rifles and Actions" wrote up the differences, but didn't elaborate on receiver design, only the improvements.
