I killed a a mature cow elk with the stainless steel Deep Six version this year at about 35 yards. The arrow was an FMJ Deep Six with mass of 472 gr.
Perfect performance.
The shot was a little high, double lung, and it hit a rib dead center on the entrance. I had full penetration, in fact it was dangling by the fletching on the exit wound. I am pretty sure it would have been a clean pass if it had not hit the rib.
The cow went about 100 yards and fell over. The arrow fell out after about 30 yards. Nice big entrance and exit wounds. The rib was completely shattered.
I chose this broadhead because it flies so well, matching my field points and grouping well out to 100 yds. I have previously used the QAD Exodus. The Exodus flies well, but the Ulmer Edge flies way better. Especially if there is any wind. I went out right before my trip and shot the Exodus and the Ulmer in a pretty stiff wind. I experienced more drift with the Exodus.
I will continue to use it on elk without any concerns.