Got started on finding the right load for the 375 today. I want to use the 300gr Nosler Partition as a allround bullet. Tested at 50m with some cartridges loaded with Vithavuori N550 and Federal 215 primers in new Norma cases.

72-75gr N550 in steps of 1gr.

The right barrel put the bullets pretty much in the same place with all loads.

The left barrel "walked" the bullets closer to the right barrel, as the the powder charges was increased.

Shot a pair of rounds of the 74gr and 75gr loads over the chronograph.
74gr gave 766ms and 770ms R/L and 75gr gave 776ms and 782ms.

Think I will load some more cartridges with 74gr and 75gr and do some more testing at 50m and 100m.