i went out yesterday to test my data.
Is this new load/data or have you shot it before?
i figured that i would have to make some changes.
Why did you think that? Have you shot the exact same gun/load combo before at this same range, and if so, what data did you get then? Did you shoot steel both days or targets one day and steel the next? How precise was your aiming point each day?
Did you do, or have you done, any work on the gun??? Scope off, stock off etc.
Have you checked everything physically with the gun that might have changed? Action screws torqued right? Scope, rings, base all tight?
Did you shoot the same number of shots, in the same manner, per group both days? Did you use the same rest and shooting style/position both times?
If you have just the two days of data and believe there is a problem, then how do you know which day produced the most accurate data?
I guess what I'm getting at is check everything you can, make sure as much as possible is the same both times and remember that sometimes "stuff" happens. Copious field notes will tell you what you did, under what conditions, etc. every time you go out.