Depending on the regs where you plan to hunt, the modern in-line muzzle loaders can be both accurate and powerful. Remington makes a M700 Ultimate Muzzle Loader that uses Blackhorn 209, a "smokeless black powder". I shoot a a 325 gr Pittman bulllet at 2325 ft/sec using a Fed 215 primer and Blackhorn 209 (Labrador measured). That's an ME of 3800 ft/lbs. This bullet has a G1 BC of 0.350. These can be amazingly accurate and can easily kill elk at a reasonable distance.
Recoil is ferocious! I put a T-Rex side-ported brake on mine. I have to go to the range by myself or do a makeshift range, because every time I fire the beast, a cloud of smoke belches forth (yeah, Blackhorn is not really smokeless) and the concussion wave blow the hats off of anyone nearby. It's considered a public nuisance. But what fun!
I put a Leupold VX5HD on it initially. The scope failed after about 80 rounds. First Leupold I've ever had fail on me. I've replaced it with a Nightforce. To Leupold's credit, they repaired the scope promptly, and it now lives on a 22-250.
Granted, this is a departure from the idea of using a primitive weapon. But with limited opportunities to draw a good elk tag these days, where these are legal they are a game changer.
A warning. Blackhorn 209 powder is vanishingly rare. With only 10 ozs per bottle, it disappears in a hurry. Make certain you have a supply nailed down before you spend the money on an expensive muzzleloader and scope.