This is gonna go against most everything you've read in the reloading manuals.
Having shot the 270 Win with 130s and 140s of all manufacturers since 1967 and having replaced the barrel once here's what I learned:
1. From the Speer #9 Loading Manual to now one of the better powders listed is 4831.
Nah! It's a dud powder. Learned that years ago with the advent of the chronograph.
No matter how much 4831 I crammed in, even to the point of expanding the case
enough to prevent chambering, couldn't get to 3000 FPS w/130s.
2. Norma 205 was THE powder to make the Winny perform. It went away….:roll eyes:
Now its back…
3. RL-22 became the goto powder. It's the same as Norma 205 was with a ton more
temperature sensitivity.
4. The new goto powder is PP-4000 MR. With the CCI-200 primer and Winchester
brass, the strongest/highest capacity cases I've come across, velocities can
approach WSM factory velocities with 130/140 grain offerings.
I've shot those velocities with N-205, RL-22, and 4000 MR for all of those years. I stopped increasing powder when velocity got to 3190 FPS which seems to be the sweet spot for that rifle with any bullet I feed it. I have cases that I have had since the rifle was put together in 1967.
Start low and work up, as usual. Each rifle is an individual.
I use the 140 Berger @ 3190 and she sure is a sweet shooter. She sports a 27" Lilja barrel. She originally was fitted with a 24" Douglas and achieved the same velocities.
The Douglas barrel was good for 3/4 MOA all day long. The Lilja is much much better.
FWIW…