I have just returned from several days Red stag stalking and for the first trime used the 140 grain .270 Accubonds, no deer were shot beyond 180 yards but each fell to a single shot.
Even where no ribs were struck expansion was sufficient to kill cleanly, even with neck shots. I have got a load that will produce a 5 shot group into 5/8 inch at 100 yards and am now sold on Accubonds 100%.
Largest stag shot had an on the hoof weight of just under 16 stones.
I have yet to read of a single make of bullet that according to someone somewhere has failed for either themself or a friend or a friend of a friend, I suppose that anything is possible. For my part however I look to try out bullets that seem to get good and consistent recomendations, and if they appear to work I will try them, for me the Accubond is one such bullet.
I think the best thing you can do is load some up and give them a try, I don't think you will be dissapointed.