What say You who have used the 7.62 a fair bit ??
Elk capable ?
what rounds?
good formula for elk/moose would be .25 sd bullet landing about 2000 fps or above for most situations, in rapid expanding construction landing as low as 1800 fps
always start with the bullet, then figure out what will drive the bullet to the speeds you want, since you're starting with the cartridge you're likely going to have limited options and range for the game intended, I believe most bullets for the 7.62x39 are .2 sd range (deer size game) and speeds pretty sad so range will be very limited with a marginal bullet penetration potential
best option might be to rebarrel to 6.5 Grendel