I got my Ritchey 27.2mm seatpost today and it is a really tight fit in my vintage steel frame.
I cannot slide it up and down, but have to wiggle it back and forth using the saddle and it is still hard and scratching the post.
Both the post and frame measure 27.2mm and the frame has little use and no rust or corrosion.
I do not feel any burrs either. I think it is close just need to take a little off the seat tube.
I am thinking of using one of these flexible hones:
https://www.amazon.com/29mm-Flex-Hon..._t1_B003V2UQ30
They come in 25.4 and 29mm. The 29mm is what people seem to recommend as it compresses somewhat.
Just want to make sure I can't damage anything if I go slow.
Another option is I have some steel conduit I could attach some sandpaper to and move it around by hand or try to attach to a drill somehow.
Since I only need about 5 inches of post above the top tube it has go really deep into the frame, so I am thinking of cutting it so it only goes about 3 or 4 inches into the frame which should help.
Thanks for any feedback.