I haven't shot anything with them. But I just built a custom cpx for a guy to elephant hunt with and we set him up with the griz stick and the ashby 315gr. Seem like a nice setup. around 1200gr. but they tuned easy
^^^^ This Mine is full length FMJ with 75 grain brass adapter and 175 head and I am at 650I recommend you see them in person before purchasing as they are quite a bit larger than a std arrow in diameter....a disadvantage. There have been quite a few complaints in the past re spine and durability....they may have the kinks worked out now.
Its pretty easy to get an excellent reasonably priced dangerous game arrow with the Easton 5mm skinny FMJ Dangerous Game shafts at appx 13gpi....then add one of the 3 choices for arrow tubes at 3 Rivers; 3 gpi-8 gpi.....those and a heavy BH and /or heavy insert gets you up to 1,000 gr pretty easily.