Try different bullet lengths in your rifle. This makes a big difference if you're after smallest groups at, say, 100 yards. Fortunately there are plenty of options. Heavier plastic-tipped bullets are longer than their softpoint counterparts. There are bullets suitable for deer from about 130 grains to 220 grains. I'd bet the shorter bullets shoot better in most guns. Try a flat based bullet unless you're shooting at long distance and need the higher BC.
Of course, anything that will group into 2 inches at 100 yards will do for this application. I tend not to worry about maximum accuracy in big game loads. I really want maximum killing power (i.e., optimal blend of expansion and penetration.)