You can't cook wild meat like beef. It will dry out once it hits medium rare... so don't over cook it, simple as that.
I cook a fair number of roasts, and my favorite way is this...
Make sure roast is room temp, very important.
Set oven to 500 degrees
Soften half a stick of butter
mince 5-6 cloves garlic
add, garlic, rosemary, tyme , and other spices you like to butter
salt and pepper the roast liberally
coat the roast in the butter mixture.
Place it in a baking dish on a rack, cook for 20 min (per 4lbs), then turn off the oven. don't open the door or check it for at least an hour. It should come out rare/medium rare. 135-deg. If its not up to temperature, turn the oven back on a low setting 300deg or so, then turn it off after about 10 min, and let it cool off again. It rarely takes more than another 10-15 min the proper temp. After the first hour its almost always done perfectly.
Just cooked a moose rump roast three nights ago like this. It was better than prime rib, and not dry at all. The wife even complimented on how good it was, and she's not a rare meat eater...
We pressure cook them as well, and also BBQ them. Key is to sear in a very hot pan, and do not over cook it. Take it out when its 135-140deg in the center and let it cool in a tent. I never use a crockpot, yuck.