Nothing really. Accuracy would be a reason to crack open the H4831 if H4350 doesn't deliver. Your speed with that 180gr should be between 2925fps and 2985fps. I used a lot of H4831 for the 338WM, the 300WM and the 270Win.. H4350 was for the 30-06 and 7x57. So, double check to make sure H4350 is good to go and sell off your 8lb. keg of H4831.
By the way, my best loads were at max. 73.0gr of H4831SC with the 180gr Partitions and 67.0 gr. of H4350 with same. CUP's are very close there also. I mostly used Fed 215's.
Good luck.
