Hey guys. Let's not dismiss the mule deer as always bad tasting. I believe if you get one that tastes bad, it is either the way it was field dressed, processed, or cooked. I've shot mule deer in northern Colorado, eastern plains, and as far south as south central Colorado. Never had one taste bad. Whether prepared as hamburger, steak, or roasts, they were delicious. My wife marinates them in milk and when she's done, well, just great tasting. $#*!, she even made an antelope taste good and I used to only use antelope for jerky.
I thought you got rid of that flintlock and bought you an inline. I believe the inline would be a little bit lighter for you and easier to carry, However, the recoil might be a little stronger due to being a lighter weight. So, I'm not sure the trade-off would be beneficial. With your back problems, maybe a crossbow would be the answer. They have some great accuracy and range.
I also agree....elk and bison are delicious. Again though, field dressing, processing, and cook prep is most important.
Happy hunting gents.