Does Remington do anything different to the Sendero action compared to the 700 ? Watching videos of smiths accurizing the 700 action makes it clear that Remington does not even bother to cut the receiver threads using a threading tool in the lathe, even though the receiver starts off as a tube ??? Instead they use a tap which results in the threads being tapered and out of square. The the bolt engagement face is not square or flat (use of a worn "plunging tool" as opposed to a "proper cutting tool manipulated in 2 axis.) Its simply pitiful how something so simple just cannot be done properly in this age of $25k cnc lathes.
I get the impression that Remington is using equipment that is probably 30 or more years old (and now considerably more worn out) to make the 700 actions and they would benefit massively by re-tooling that line to use modern equipment that will build the quality back into the products. But, presumably, as long as people keep buying this sh**t, they will keep making it and change nothing.