Once the velocity went above 3000 fps the GCs started coming off. They do considerable damage to the SkyScreens which I'll post later. As I've stated and posted numerous time the best consistent HV accuracy of 1 - 1.5 moa (10 shot groups) comes just over 2900 fps. At 3100 fps the 10 shot groups opened to 3.75" with every flyer being also a bullet that lost its GC as seen when the SkyScreens were struck by the GC. Also at 3100 fps the bullet out of the 16" twist is at the front edge of the RPM Threshold.
In the NRA Cast Bullets Supplement Col. Harrison notes in the article starting on page 108 the success with the 160 gr PP'd bullet in the 300 WM with the full load gave an average of 2.6 and 2.2 moa (five 5 shot group average). Unfortunately, the pressure and velocities were only estimates. Also he did not recover any bullets or patches so we don't know whether the patch was "burnt" or not of if the base of the bullet was damaged.