I put a 24" PacNor 3 groove #5 contour on mine. I wanted the extra weight of the heavier contour for recoil reduction. It was a rebarrel of a Winchester push feed 264 win mag Model 70, which is not a light action either so the gun is a 11 pounder all loaded up but is easy to shoot.
Since the 375's are reputed to do well with powders in the RL15 to IMR4350 range, I decided from the start to use RL17. With no reloading data I started low and worked up which is what anyone should also do if using this data
BULLET WT PWD CHARGE OAL FPS
TSX 270 RL17 74.0 3.285 2552
TSX 270 RL17 74.5 3.285 2564
TSX 270 RL17 75.0 3.285 2578
TSX 270 RL17 75.5 3.285 2564
TSX 270 RL17 76.0 3.285 2572
TSX 270 RL17 77.0 3.285 2573
TSX 270 RL17 78.0 3.285 2621
TSX 270 RL17 79.0 3.285 2643
AB 260 RL17 80.0 3.350 2760
AB 260 RL17 81.0 3.350 2798
AB 260 RL17 82.0 3.350 2849
TSX 270 RL17 80.0 3.285 2692
TSX 270 RL17 81.0 3.285 2714
TSX 270 RL17 82.0 3.285 2753
AB 260 RL17 82.5 3.350 2859
AB 260 RL17 83.0 3.350 2872
AB 260 RL17 83.5 3.350 2896
AB 260 RL17 84.0 3.350 2916
AB 260 RL17 84.5 3.350 2938
AB 260 RL17 85.0 3.350 2941
AB 260 RL17 85.5 3.350 2956
AB 260 RL17 86.0 3.350 2978
AB 260 RL17 86.5 3.350 2996
As you can tell I was looking for max load with RL17 and never did get any pressure signs. Here is a pic of the primers on the last load listed
But I got better accuracy with the 270 TSX and felt more comfortable running it at 2850 to 2900 fps
But it is possible to run the 260 Accubond at close to 3000 fps which would mean it would have the trajectory of a 270 winchester!