I asked Berger and they sent data for RL-26 and 140 grain. They said RL-26 was too slow for the 130 class bullets.
I have used it in my .260 AI, so a little different. With a 29" barrel, and HBN coated 147's, I am getting 3050 fps with 50.XX grains of RL 26 seated to 2.900" OAL. DO NOT try this in a standard .260, my loads are not only in an AI, but are also HBN coated. My max was about 50.0 grains or so at 3100 and change with naked bullets, it shoots best at 3050 though. I would start around 44ish or so in a standard .260 and work up 1 grain at a time looking for pressure in a standard .260.Any load info anyone wants to share with 143 or 147 in a 260 and RL26? Thanks