captdavid,
The reason the 175 roundnoses work so well in your 7x57 isn't because they have round noses, but because of the moderate muzzle velocity.
There were three reasons for round-nose bullets back when smokeless powder started to become the In Thing:
1) Most early smokeless rounds were military, and since previous black powder military rounds mostly used heavy, round-nosed bullets, that's what were used in most early smokeless rounds. But the switch to lighter spitzers started shortly, and was pretty much complete within 50 years.
2) The prevalence of tube magazines, especially in lever-action hunting rifles, made blunt-nosed bullets a necessity, in order to prevent setting off the primers of the rounds in front. But with Hornady's FTX bullets even that isn't true anymore.
3) Many hunters believed blunt-nosed bullets "busted brush" better, but that turned out to be BS.
4) Many people found that early round-nosed bullets sometimes expanded more reliably that early soft-nosed spitzers, but that's pretty much been solved for decades now. I used to use the original 200-grain Nosler Partition in the .30-06, a "semi-spitzer," at about 2550 fps for timber hunting, partly because it was the deepest-penetrating bullet available back then, and partly because it killed well due to the soft front core expanding easily, but didn't shoot up much meat.
But if you really want to use a blunt-nosed bullet, plenty of company still make them in .30 caliber, in weights from 150-220 grains. Probably the 170's made for the .30-30 would work as well as the 175's from the 7x57 if loaded to similar velocities.
