Re: 270 Win / 700 Rem mt. rifle
Jim, the first thing I'd tell you is that most of the reloading manuals, especially Nosler, print velocities that I've never been able to achieve. I think they get a figure and add 200 fps. Years ago, I went to a range after I had been loading for 3-4 years and a guy showed up with a chrono. He offered for me to shoot my rifle so we could see what it would do.
I was shooting 130, 140, and 150 NBTs with IMR4350, H4350, and 4831 each. I had some max and near max loads and not one was even close to published velocities in the manual.
Sometime later, the same occurred in a 30.06 with Speer bullets. So I just considered published velocities to be a bit embelished.
Reloder powders have been top producers of velocities for me.