I'm a little in the same boat. I've semi-recently acquired my first 30/30. I've hunted with scoped rifles since I was 14 and when this came along, I decided it's time to scratch that itch of heading afield with a peep-sighted something or another. Bought my dies and cases, and of everything that happened to be on the shelf of my local toy store (which wasn't a bunch), I decided on the 170gr Sierra. The comments here confirmed what I was thinking. Trajectory-wise, there's probably not any difference that I will notice in the field, so may as well go heavier. I would use my rig for javelina, and perhaps cow elk.
