.30-30 bullets in a .30-40 work great, as noted. I've found that Sierra Spitzer 125 gr. bullets work perfectly for deer in a .30-40 case. You need to increase the recommended loads for the .30-30 a hair to compensate for the lower pressure in the larger case, but it doesn't take much experimentation to get a nicely balanced load. Less kick, good expansion and penetration--you don't need an elk load to kill whitetails or blacktails at normal distances. For big mulies in big country, I'd go with a different bullet/load, tho.
