I've used the 200 grain Swift A-Frame for animals that size both in western states and in Africa. While I shoot a .300 H&H it's reasonably the same as a win mag.....This has worked very well for me but 180 grain bullets would also do the job.

I wouldn't go lighter than 180 grain except for the monolithics and then 165 is as far as I'd recommend.

150 ballistic tips will do the job but if you don't get the shot you want and have to take a raking shot you'll wish you was shooting heavier bullets that penetrate deeper.

180 grain partitions seem to be the standard bullet for this job in .30 caliber. Accubonds 180-200 grains will also be effective as well.