mtnbound,
I’m a little surprised to hear that. But obviously every barrel is different.
I’ve burnt out a 243Win & 6CM using SB6.5 almost exclusively as the propellant. (A small amount of H1000 in the 243 early on.) Great velocities and accuracy. And now working a new 6GT with very promising early results.
IME, you’ve got to step on the gas to get the best performance out of SB6.5.
42.5gr and 43gr was what I tested and I had 2716fps and 2779fps for averages but had SDs over 70fps in both.
What was your recipe?