Sadly I no longer own a 257W, as my .257W, 25-06AI, and .224 Clark were stolen about 2 years ago.
However, I still have the chrono data that I worked up in my Custom 257W, with REM 700, and Krieger 26 inch 1 in 7 twist barrel. (no freebore)
Using Norma 257W cases, Federal 215 primer...