Well I own a few so calles failed cartridges, one being my favorite for mid sized game the 264, it failed because of one particular writer like well the 270 (fine cartridge) and one other that liked the 7mm mag humm! I think its far from failed me but does lack in some aspects but not many if used for the practical use.
The others i own are the RUM familt and the STW family , yes i will say expensive, not very efficiant for the powder burn, and hard on cases. Simpley put the 7mm RUM and the 7mm STW and yes fast but does not completely knock the doors off the 7mm mag i have? cronnyed them all and theres not that much more and at 500 y well who cares.
Another not failed cart but one i feel has a big bark very expencive brass/powder is the 30-378 whick i own one and really in the big picture is not that much more than a 300 wm loaded up! yes its fas yes it hits harder but!! 115g ov pwder vs 75 humm!
well no cartridge has failed in my eyes there are just better case designs that improve velocity/accuracy , lower recoil and efficiancy of powder burn, get that combo right and its a good sell, vs the opposite some cartridges were promissed to do more than there intent, and failed in the field with lack of knowledge to the hunter when he pulled the trigger, more so in africa.