The 270 Winchester is essentially a long-range, big-game, bolt-action, rifle cartridge. So don't brag about, or even count your 100 yard groups. They don't mean squat. If 100 yards even matters, then all we really need is a 30-30 or 44 magnum carbine. The 270 is expected to take Deer or whatever at 300, 400, or more yards. You should never take a shot on a Deer or Elk that's beyond the range that you actually shoot your rifle at with some degree of regularity that could engender some confidence. I don't care how accurate of a 5 shot group you may get at 100 yards; you cant count on it to maintain the same stability, or MOA, out at 300 or 400 yards. It's alarming how many promising 100-yard-excellent load recipes go all to Hell at 300 yards. Like one-inch groups turning into 16" groups.
Not to hi-jack the thread; but whats your most accurate 270 bullet at 300 or more yards. 5 shots or more, now......
For me, it's the Nosler 150 grain Partition.
Rifle: Winchester model 70 Classic Sporter.
Powder: Norma N-205; good luck finding any.....
Brass: I like Winchester, but my rifle says Federal......
Primer: CCI Large Rifle, but I expect Federal and Winchester might be OK too.
I won't say how much powder except to say velocity is running right around 3,000 fps.
I use Sierra 150grain Game Kings as a preliminary substitute when experimenting with load-work-ups to save on the more expensive Partitions, but switch over when things look promising.