Re: 270 win & h1000
Way too slow of a powder. . .
If you're milking the Nth degree of velocity Norma MRP, N205, RE-22 and some are using 7828ssc with 150 class bullets.
If not pushing but looking for moderate range accuracy, any of the above powders loaded down a bit and 4831 around the 60 grain mark should produce accuracy.
I'm a velocity hawg with the little winnie pushing the 140s @ 3200 with Reloder 22, in the summer time. Temp drops it a bit in winter. But it shoots very well at that velocity and good for out to 800 yards or so.
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!