My wife and I are just back from Deer and Elk hunting. Wife had either sex deer and either sex elk tags. I had nothing tag wise so I was the step and fetch it. Wife shot a 5X5 Bull Saturday and a 5X5 Buck Sunday Morning. Both were shot with her 270 Win. loaded with 140 grain Hornady SST's driven with 59.7 grains of RL-22 with WLR primers Winchester cases. Both animals were shot in front of the shoulders and both dropped in their tracks. Meat damage was minimal. The elk shot took some of the lower vertebra process as it went through. Deer shot was lower and broke the sternum and sucking out a goodly portion of the lungs. I can't comment on the 6.5 X 55 as I have never owned/used one.