I understand that BC is a large part of the terminal ballistics of a load, but there is also the matter of energy transferring from the expanding powder to the bullet itself. When a bullet becomes larger and must be seated deeper, it's extra size comes at the expense of case capacity. For instance, the 175 and 180 grain SMK's have virtually identical BC's between 2800 and 1800 fps, but the heavier 180 grain bullet will need to be seated slightly deeper than a 175 grain bullet, correct? That would mean that the slightly smaller bullet with the same BC may have an edge because it would allow for more propellant which means a higher muzzle velocity and energy.

My question is whether the standard 180 grain hunting bullets are much more available because the amount of powder being lost is inconsequential regarding ME and MV, or if it's because the larger cases of the 30-06 et al., are better suited to the heavier bullet and it's cheaper to produce one bullet that works decently in all .30-cal weapons.

If it doesn't make one bit of difference between the 180 and 175 grain bullets, then I was thinking of a 180 grain Partition or Ballistic tip as being my load of choice. If there is a substantial difference between the 175's and 180's, then it may be worth it to try out those 175 grain VLD's.