Good Morning Picher,
I honestly don't remember how much of a shift there was between the two loads, but we alway re-sighted our rifles. We spent most days feeding cattle and shooting against each other on smaller ranch targets that were in abundance near the ponds and creeks, so missing was not a good thing.
I am heading up to my desert house this weekend. That is where I store that rifle. I have a bunch of the 70 grainers loaded up, so if a get the chance I will shoot some groups. It is supposed to be windy, so not sure if it will be conducive to accurate shooting.