Has anybody used this ammo? And if so did it achieve the advertised velocities?

I have used the 300gr solids and took a buffalo with them. I have never chronographed them but they are noticably faster than standard ammo. The ones I used were the old style steel encapsulated. I have some of the newer ones in 458 win mag but haven't tried them yet. Great penetration but not the most accurate, they are plenty good enough for Mr. Atkinson's "minute of buffalo"

In my rifle the accuracy was only so-so. I also found that when I chronographed the loads, the velocities varied by as much as 95 fps 10 yards from the muzzle.