I just got a 300 RUM and have been researching this topic for a while.
I think the idea of carrying short to midrange bullets along with a LR bullet/load combo is a good idea. Of course, one bullet would be best and I may be able to do that.
Here's my approach and bullet selection...
Short-midrange out to 800 yds give or take
180 E-Tip, BC .523, MV ~3300+
200 AB, BC .588, MV ~3200
Long Range, over 800 yds
210 JLK VLD, BC .665, MV ~3150
210 Berger VLD, BC .616, MV ~3150
177 GS HV, BC .638, MV ~3500+
Different rifles like different bullet/load combos. For short range I'll start load development with the E-Tips because I like monometal bullets. If they dont light my fire then I'll try the 200 AB's. For LR, I'll start with the JLK's because they show a better BC, but that may be questionable and BC will always have to be verifeid on the range with any rifle/bullet combo.
The 177 GS HV's give better velocities per weight, as much as 100-200 fps over other similar weight bullets. They are reported to be excellent killers. They are monometal and at higher velocites they will shed their petals, but they will still do a lot of permament wound channel damage with their squared slightly mushroomed frontal. The Jury is still out on their BC, but if it's close to advertized it will out run any of the other bullets listed and take you well past 1K. I think they are worth trying... no guarentees yet. And they cost over $1 each, but they are also advertized to add barrel life which is a big plus for the 300 RUM. Twist may be another limiting factor with the GS's
GS CUSTOM BULLETS - Recommended Use and Technical Data
Good shooting and keep us posted on your developments.