My pet load for my Merkel 9.3x74R is f/l resized RWS brass and 57.4 grains of Varget and a 250 grain TSX or TTSX, and a Winchester large rifle primer (non magnum). I'm pretty sure that Varget is the North American label on A2208 powder.

For those with a Harrel powder measure, the setting I use is 100.0 0/3 culvers....

With this load, I get a perfect side by side 1 inch composite group at 100 yards, perfectly oriented right and left on a horizontal plane. This rifle is my most perfectly regulated double when using this particular load. The rifle can sometimes demonstrate slight stiffness of the top lever on a really hot day - indicative that I'm riding toward the edge of a hot load in this rifle.

The factory target shows a ragged one hole group at 50 metres with RWS 286 grain loads, but I've never been able to even remotely duplicate this with 286 grain bullets. The 286 grain bullets orient diagonally and I haven't managed to find a powder that brings the shots together. The 270 grain Speer bullets get the groups tighter than the 286 grain loads, but are still dismal. At least the 270 grain bullets are more horizontally oriented, but are still not great.

In any event, every rifle is different with its own unique personality, and this attribute is much more highly pronounced with double rifles when developing suitable loads that regulate properly.