ASbobcat - nice explanation - your results are very similar to mine: Stiller Diamondback, Bartlein 1:8" twist, 26", .246" NK, turned for .002" total clearance. The barrel "liked" just short of 35.0 Gr. of RL-17. As you noticed, I am pretty leery about sharing load info, where there is little published DATA from the powder manufacturer.

When I want speed, and precision, RL-17 gets a look -it's very impressive in the .220 Ackley Swifts, and, via the .257 (Roberts) Ack. Imp., it's as if Alliant formulated this powder for the specific cartridge!

May see ya at Mt. Palomar!

RG