I got some for my 25 wssm a little over a year ago and got around to using it last summer. It'll do 3300 fps with a 100 gr. and hold decent accuracy at 1moa. h4895 is better accuracy (1/2 moa) but only 3150 fps or so. Don't have a 300 wsm though so I haven't gone there.
Just tried 70 and 72 grains below AB165's today. Performance was approx 3200 and 3300 fps respectively. OAL was 2.860", mag primers, 26" barrel, Remington B&C rifle.
Rifle is bedded, 3.5 lb trigger, muzzle break - first day shooting the rifle. Tried a variety of powders and the Super seems super! Sub-MOA at 100 yds with both loads but the 72 grain load was tighter with two touching, other 3/4'' out on the horizontal.
Am doing the same load after a good cleaning with 168 e-tips also.