Good advise from Blackelk. With proper bullet placement into the vitals of deer and deer size animals, I've never found them hard to kill.
For over 30 years, my favorite bullet for deer, antelope and several bighorn sheep was the Sierra GameKing. A few years ago, I changed to Nosler Ballistic Tips because they were a little more accurate in my rifle. All of the deer and antelope that I've shot with the BTs died just as quickly as the ones that I had previously shot with other bullets. Placement counts more than make of bullet.
I also used Nosler BT bullets in a 7 Rem mag on my first South African hunt, cleanly killing 9 animals from Kudu down to bushbuck.
The Nosler Accubond bullet is the same construction as their BTs but with a heavier jacket which gives more penetration.
I used Accubonds in a 7 Rem mag on another South African hunt, and again cleanly killed another 6 animals with them. One of my Professional Hunters was very impressed with the wound channels that the Accubonds made.
I have also used Accubonds in my 7mm Rem mag on several other Montana and Canadian hunts, all with good results. The 160 gr Accubond in my 7 RM is my backup elk bullet and rifle.
Barnes TSX bullets were also mentioned. I have found that the TSX and TTSX bullets are very accurate in two of my rifles, and they perform very well on game. I hunt exclusively with TSX bullets in my .375 RUM and with TTSX bullets in my .300 Weatherby, but these rifles are not my first choice for deer hunting.