Does anyone have any familiarity with the .257 Shooting Times Westerner? I am thinking of having my Sendero rechambered/rebarreled for this round. What I have heard about it sounds good, except for the quick barrel consumption of course. Any info or load data on this round would be appreciated! Have a great Day!

I just built a 6.5 STW and am working up loads. I thought it was extemely overbore. I used an internal ballistics program to get started. For the 6.5 STW I had to use the slowest powders I could buy including H1000,IMR7828, and RL25 for the light bullets(yes the light bullets), and H870 and H50BMG for bullets heavier than 120grains. For example, 120 gr. Nosler ballistic tip and 92 gr of H870 yielded ~3600fps. Where RL 25 would give the same result ~82grains. I suspect You will need to use H870 for 115 and 120 gr bullets. With 95 gr Hornady VMAX I used 82.5 gr of N560 which yielded 4000 fps. I suspect you could get about 3800-3900 (28"barrel) with the 100 gr. Nosler ballistic tip. I would use either H1000 or H870 and start really low ~75 grains and test fire remotely while looking for pressure signs and work up as indicated. You will have to generate your own loading data. A chronograph is essential. Or you could just get a 6.5 STW shoot the same weight bullets a little faster and have much better ballistic coefficients with your wider choice of bullets(eg. 95gr Hornady VMAX BC=.395 100gr. Nosler BT BC=.393).