Trim and remove any silver skin from the tenderloins; place on a plate or small platter and set aside. Grind juniper berries in a spice grinder or mortar and pestle then transfer to a small bowl. Mix in the salt and pepper thoroughly. Sprinkle rub on all sides of the meat - use all of the rub. Loosely cover with plastic wrap and set aside in the refrigerator to cure for at least 4 hours and up to 3 days.
Remove venison from the refrigerator 45 minutes before grilling to take the chill off. Set up grill for grilling over direct high heat. Brush and oil grates before grilling.
Make the Blackberry Sauce.
Drizzle the tenderloins with a little olive oil and turn a few time to make sure they are very lightly coated.
Grill tenderloins for about 14 to 18 minutes total, flipping very 5 minutes. Remove from grill when the internal temperature reaches 140°F. Transfer to a cutting board and tent with foil to rest for 10 minutes. The internal temperature will rise another 5°F to 10°F.
Slice tenderloins 1-inch thick on the bias. Serve with Blackberry Sauce.
Recipe by Grilling Outdoor Recipes powered by Bull Outdoor Products at http://www.grillingoutdoorrecipes.com/juniper-rubbed-venison-tenderloins-with-blackberry-sauce/