Sous Vide is the only way to go with lower end roast cuts of beef if you want them tender and med rare. I have been buying a lot of Sirloin Tip and Rump Roasts when they are on sale. I fry a mix of onions and mushrooms add all my seasonings to them. Coat the roast in that mix,seal up in a vacuum bag let sit over night. Six to ten hours sous vide at 130 to 135. Remove from the bag finish off on the grill just long enough to get a good char over a hot charcoal fire. Will be a perfect med rare to med depending on the temp you went with. I usually go 135. A touch more than I like but I can tolerate it others in the house will not eat anymore rare than that. I slice it nice and thin. But you can seriously cut half inch slices that you can cut with your fork it is so tender.
Yep - it is stunning what you can do with a Sous Vide to tough just of meat. My moose from last year is very substandard in tenderness compared to the one I shot 5 years ago. All of us in our group commented on all three of our moose and we think largely a bad butchering job and not enough time hanging is the cause. Cooking via Sous Vide works great to make it as tender as previous moose.
