I have used a 7mm rem mag for nearly 20 years.
Over that time have used a few different sorts of bullets of varying weight.
If you want reliability of good expansion but NOT blow up, stick to a heavier well constructed round, like partition, grand slam, etc.
Threads like these make me laugh, you have bought a magnum and moan aboat the cost of feeding it????
How many deer do you shoot a year for the extra 20p a shot to make any difference. Stick with what you know and the damage you find acceptable, if they work the venison you save will be more then 20p's worth.
If cost is an issue just buy a .243 it uses about 35-42gr's of powder rather then 60-75gr's think of the saving.