Quilly,
I have been using Speer Nitrex in 180 gr. Grand Slam ammunition in a 300 win mag for the past couple of years now. They group excellent and are a very tough bullet. However, I won' t recommend them for deer. Two years ago I took a white-tailed buck in Saskatchewan with the Grand Slam. The exit hole was no bigger then the entrance hole. It was a double lung shot but the buck still managed to run 400 yards. Didn' t matter much as it was in a barley field, but it if would have been a problem in the bush with the smaller exit hole, making a difficult tracking job (the shot was just over 200 yards so the bullet wasn' t travelling all that fast). Now the good news. Last year I was able to take a bull elk. I intentional shot the bull in the front shoulder, as we were hunting up against a national park and didn' t want the bull to run off the legal land and make its way into the park. Anyways, the bullet smashed through both shoulders and what was left was lodged up against the skin on the far side. The bull went about 10 feet (shot was 150 yards). The bullet preformed prefectly. Thus I would only recommend the Grand Slam on tougher game like elk. As Skeeter mentioned, I have since changed to the Hornady SST for deer.