I was wondering if it is possible to move the front small rail that is on top of the barrel to the underneath position of the barrel on the R-25. I'm looking to add a bipod to it and I don't want to use the swivel mount type.

Rick, I see your post is 6 months old, but no one had responded. The rail you speak of is on top of the gas block, and that cannot be turned upside down because of the gas flow through the gas port, through the gas block and into the gas tube. You could however , replace the gas block with one that has rails on the sides or bottom.
Mounting the bipod on the gas block would put pressure on the barrel, changing your point of impact. Much better to mount the bipod on the swivel of the free floating forend, that way pressure from the bipod would not affect the accuracy.

Hey sandog, thanks for the very informative reply to my question. I appreciate that.
I went ahead and installed a Harris swivel bipod a few months ago and am very happy with it. The info you posted though is very good to know.

Welcome back to the Remington Owners Forum RickT !!