All cartrige's have an optimum load ( the best all round weight,velocity,
Ballistic coefficient/energy) with the 300 rum it appears to be between
180grs and 200grs, this does not mean that other bullets wont work but
may not utilize the cartrige's potential.
165 ballistic tips do work in place of 168 SMK's but were intended for
the slower 308 win.
The 165 will produce more velocity and less recoil but that's about
the only advantage in the big magnum.
I have 2 loads for mine they are the 180gr accubond (a little tougher than
the ballistic tip), and the 200gr nosler partition for the big stuff.
Just my 2 cent's
J E CUSTOM