My 257 is built on a 98 mauser action. I have always shot 120 gr Hornady HP with 70 grs of RL 25. That is Max so start about 66 grs and work up if you try that. Also in the process of trying 100 gr Barnes TSX and TTSX bullets. H4831, RL 22 and RL 25 all shoot well but Rl 22 may be the best with the 100's. Strangely my rifle does not care for 7828 powder.
Man it has been years. It was a 115gr Part and 69grs of MRP. He told me he switched to RL22 when MRP was hard to find. He had to tweak it about .5gr but I can't remember which direction.
As usual just my $.02 Paul K
Posts: 12881 | Location: Mexico, MO | Registered: 02 April 2001
All guns are different, but I have had 5 .257wbys and they all have excelled with RL22 and heavier bullets loaded to the high end of published data. And Federal 215s.
Posts: 849 | Location: MN | Registered: 11 March 2009
