Practice like you intent to play. If you want to be proficient with your hunting rifle than you need to log some time getting to know it. Granted there are some similarities and commonalities from platform to platform, but there is no substitute for training with the tool you expect to use when you find yourself in the moment of truth.

I've got a lever action .22 that I love to take to the range and run a bunch of rounds through. "Practice" with this rifle helps me tune up certain skills related to the fundamentals (grip, stance, sight alignment, sight picture, trigger control), but when the stress is on the devil is in the details. Unless you spent some time building muscle memory with the weapon in your hand, you shouldn't expect to mange it flawlessly when under a bit of pressure.

In a perfect world, I say go for both, but if you have to choose one over the other get to know your killing machine even if that means spending a bit more to do it. This is of course assuming you stick with the notion that bringing home some groceries is the priority as opposed to shooting for fun.

With some good instruction and oversight you shouldn't need to put too many rounds through your hunting rifle to start feeling comfortable with it and putting the rounds where they need to go.