Y33611,
IMO "skidrow" is right about them being velocity sensitive and "mule deer" recalls that some worked well in some cartridges and some didn't. I've read many stories about good performance with 130 gr. 270 on elk and many stories about bad performance in 30 cal.
I quit using them many years ago, because of this variation in performance--and not just in my personal experience but many other hunters I knew, in cartridges from the .270 Winchester to .375 H&H. Have described many of these examples in various articles and books, and these days am very puzzled why anybody would choose to use them in anything except in low-velocity rounds like the .30-30.
