110 Storm

Just got my new 110 Storm 243 left hand 2 weeks ago . Took it to the range the other day and used a load my Model 11 TH liked 75 gr. V max over 40 gr. of Varget . Once I got it roughly sighted in it was shooting 1” 1/2 in groups so I figured I need to find a different recipe . I had also loaded 5 70 gr . Sierra Blitzking and 5 75gr. Sierra Hp . Both over 40 Varget . The 75’s were low and right and scattered . The 70 ‘s were 3 in. low and 2 in. right but a real nice group . My question is why would the 70 ‘s be low when the 75 V max were right on ? I had thought if anything they would be high , seeing that they are 5 gr. Lighter than the Vmax .
I went back to the range yesterday with more of the Sierras and sighted in scope for them and are showing promise . Barrel was getting hot so I quit for the day .

Pressure and spin drift?