For your 300wsm, I'd pick a mid weight bullet designed for penetration with elk being considered first. Any bullet that will kill an elk will kill any mule deer at any sensible range. I would look at 180 gr Barnes TXS, Nosler Partition or one of the core bounded bullets; which ever was the most accurate. I'd bet my favorite A-Bolt that the only time a TXS or Partition ever failed was when the shooter missed the target.
the best performing bullet i've tried is a hornady interlok. they are cheap and perform super good on all kinds of game.
i used a 150 gr on mule deer, whitetail, hogs, antelope and everything under the sun. until i switched to a 150gr barnes tripple shock.
ballistic tips and v-max and g-max bullets DO NOT penetrate efficiently because often, they expand very rapidly and fragment in the body. i have witness this MANY, MANY times. however, these bullets will drop a smaller animal right now! because the fragments do so much damage.
bullets that have great reputations are the swift a-frames, the barnes tsx and trplshock (hollow point) berger vld's, and the nosler partitions.
I don't own a 300 but in my 7mag the barnes tsx has been deadly accurate and has performed extremely well. I have killed animals from coyotes to elk with full expansion on every one and nearly all pass through shots as well. They are not cheap but they will never let you down.
So what does your rifle cleaning kit look like? Is it a mess of bore brushes, different solvents and oils? Here may be the answer for you. I’m not going to recommend on how to clean your rifle or shotgun since you should already know that but suggest a way for you to keep all your supplies organized and where you can find them without getting four or five different boxes out to get everything together. And if you are like me and have a half dozen different calibers and...