why can't you enterchange armour alloy frames and barrels with the blued and stainless barrels and frames. I was told you couldn't do it a long time ago, but I would like to know why.

the platting that T/C used changes the size of the pin holes.
I have not done it but i have seen that you can ream them out your self, or better yet send it to T/C and let them do it for you. then you can use both the S.S. and blued barrels on a A.A. frame or the A.A. barrel on the normal frames