Hi Steven Ashe,

With a case the size of the .300RUM if I were using 165 grains on any game, I'd be very inclined to only use premium/bonded bullets. And then most likely only on light medium game, (deer). Bullets of 180 grains or even 200 grains and more are what is needed to make the really large cases perform like they can at all ranges, especially long ranges. The superior sectional density of the long, heavy, bullets rapidly overtake the shorter, lighter, bullets within the first couple of hundred yards. And assuming similar construction they will outpenetrate at all ranges.

With premium bullets of 200 or more grains the big .300's behave on game like the "third of an inch" magnum bores. Heavy bullets and big cases in .30 caliber effectively "up-bore" a size! (But only with premium bullets!) As well as improving the long range trajectory and wind drift characteristics.

The only disadvantage of the heavier bullets is increased recoil, (and less expansion on really light game).

Good luck.

Dave