MSR droms filled with water will help get you there. If you mix one or two with the items you'd normally take, the water can sub for the weight of food, or you could use the weight of water, which is easy to measure, to help you train.
I like that droms are more realistic than more arbitrary weights too. I always keep one in the bottom of my pack and routinely fill it for camp water, setting it against the frame. If you figure even a light hunting pack/frame set up is going to weight 4#-6#, then you've got food, optics, tarp, extra clothes, and miscellaneous BS weighing at least another 8# to 10# and maybe more, 6L of water at #13 is already getting you in the ballpark of a hike-in weight, with the plus that you can fill your pack with the gear that you'll take on your hunt, rather than simulating.