So I still have a question about bigger roasts. The elk sirloin roast has to be 5 pounds. Would a long brine be adequate for salt to penetrate or should I plan on injecting? I've never done that before but could certainly pick up the stuff to do it.
You can do both.
I have heard some people say "brining does not enter very far in large pieces of meat". That may be true, but I believe it makes a world of difference in the flavor. Injecting also adds lots of flavor. I also add garlic cloves by making a slit and press them into the roast as well.
Oops forgot, brine in the fridge (if you can) for 24-48 hours. Usually 24 hours was good, I never had the patience to see if 48 hour made much of difference,
