Thanks for the clarification Green_Frog; I misunderstood the term "plain base."

You may be right about the practical effects of tail shape. At supersonic speeds, nose shape is generally thought to be quite important, with the tail shape less so. I had been running numbers using Hornady bullets, but it finally occurred to me to try Sierra bullets. Sierra publishes more extensive BC data than most other makers, and these include adjusted BC for speeds below Mach 2.

One might look at their 180 gn .308s, which have an SD similar to that of the bullets used for Schuetzen in the .32-40. Here are the estimated drifts caused by a steady 5 mph cross wind over a 200 yr range, with all bullets starting at 1500 fps; all stay supersonic to the target:


RN          4.3
SP          3.6
SPBT        3.0


Going to a pointy nose drops drift by 16%, and then adding a boat tail drops this another 17%. There are more radical nose and tail shapes than what Sierra uses. There are also stiffer cross winds. 

For reference, the SPBT drift at 1000 fps (subsonic) is estimated to be 2.1"; at 2000 fps, 2.3"; at 2500, 1.6"; and at 3000, 1.3". For a 10 mph cross wind, the SPBT at 1500 fps drifts 6.0"; and at 15 mph, 9.0"; so drift at 1500 appears to be pretty much proportional to wind speed (a result not unexpected).

Of course, gusts are what cause problems; a steady wind can be dialed out. How much such drift numbers mean in practice I certainly don't know. I'd guess that at Schuetzen speeds, improvements in bullet shape might be good for an inch less dispersion in annoying winds--not a lot. As mentioned, I can imagine some practical problems with BT spitzers in lead.