I use alot of different powders year round, with the exception of AA and Ramshot, and I notice a little difference in velocity, but not alot. I usually adjust my Ballistic Card according to the conditions I'll be hunting in.
For instances; if I'm hunting groundhogs with my .243 Win and a Hornady 75gn HP/IMR 4895 in 90-80 deg temps., first thing I do after I've found an accurate load is chrono that load at that temperature, and at the same time check my zero. For "whistlepigs" I like the zero to be approx. 3-3.5" high @ 100yds and dead on at 300yds. I make my card up and use that as long as the ammunition last, the conditions persist or the groundhogs wave a white flag
After I print out that data, I cut only the necessary info out, write the load data on the back (i.e. cartridge/bullet/powder/primer/case/OAL/velocity/date) and the atmospheric data (i.e. wind/temp/humidity/barometric pressure), then I laminate it so it can easily be taken and replaced from behind the nylon cartridge carrier on my rifle stock.
Later, if I switch to the 95gn Ballistic Tip/Viht N560 in 60-50deg temps., I make a card for that only after I chrono the most accurate load.
This is not the preferred method for everyone, but it works great for me, it's quick and it's accurate. JohnnyK.