Here's a link to some .257R loads and data.

Some B.S. too... But this IS the Fire....

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/10301462/5

100 TTSX or E-Tip at 3,250 fps over H-100V, the velocity champ, is a proven killer.

115's with H-4350 work well, too.

DF