So far this year I have taken a cow elk and pronghorn with the 199 absolute hammers (I think they changed the name on these recently).
Cow elk was at 423 it was an angling to shot entering her left shoulder and I found the bullet and one petal on the top of her right rear quarter. I pulled the shot a bit so it was not ideal but she was down in 20 yards. I threw the round in my pocket but I must have lost it on the way home so I do not have photos.
Pronghorn was at 240-250. This hit rib bone and was quite devastating on the exit wound. I was supposed to use my 6.5-284 with 139 absolute hammers, but had some issues so I brought my 300 win mag. That said With 199s at 3000+ fps. I think any bullet would be pretty devastating on a pronghorn.
Two more tags to go. Hopefully I will get the 6.5 shooting better and I can have some info on the 139 grain absolutes.
Being in California I only load copper, as it’s easier to just use the same bullet even if I traveling out of state. They seem to shoot well, I like them more than the barns LRX I used to shoot. But it’s not magic. If you hit lungs they go down.
If you want to take pictures, and be part of the club, use a frangible bullet and document it. If you wanna kill an animal just as dead, not worry about lost meat, take hard angle shots with confidence, but not be part of the club, using copper works great. I've probably been using them as long as anyone around here (Barnes bullets from 1994 all the way through 2024). Hammer bullets are a great design differentiator from Barnes and other mainstream copper bullets. That said, I have zero reason to change from Barnes in any of my rifles.
I have some Hammers for my 35 Whelen AI. Honestly, no reason from a performance perspective of 30 yrs and many critters (and many calibers) from pronghorn to whitetails to muleys and elk to make a change from the current TTSX lineup.