One gun was a custom Shilen 26" with a 1-12 twist minimum spec short leade chamber. In this gun, the gunsmith in Texas recommended the following load and I never altered the load due to the low pressure and extreme accuracy:
Win Brass
Fed 215
58.0g of R#25
Sierra 117g Flat Base seated to kiss the lands
3350 fps
.450 three shot groups
the very faintest pressure signs on case head; max load for this rifle; used Bonanza neck sizer to bump back shoulders on cases .002 for subquent firings
The 1-12 twist in this rifle would not stabalize a 100g Sierra BT, Match, or any Nosler bullet, only the 100g Sierra flat base and the 117g Sierra Flat base. These were the loads that were recommended by the gunsmith, he has built a solid business on the Shilen 1-12 with the 100 & 117g Sierra Flat base bullets with these loads. I never tried any other variations on the loads that he recommended due to the extreme accuracy and speed, which is not normal for me to do.