Re: speed guess
Definitely shoot over a chrony to see what the bullet is really doing. There are so many variables to consider that speculation is not a good place to be.
I have not used Quickload before, but when I shoot an accurate load, even when I think it may be hot, over my chrony, I find that my velocities are actually within the safe realm.
Powder variances from the lot the book was tested at to elevation to barrel twist and length all contribute to what the reality for your gun is.