RE: Muzzleloader scope
Nikon, Bushnell, Burris,Leupold are all good scopes. Depending on what you want to spend is the issue and what you want the scope to do. When I look at a scope I want 3-1/2 inch eye relief minimum. The better the glass the more they cost, although there are some good bargins out there.
If you shoot extreme ranges where you hunt, then you might want to go with a 3-9x40mm in the mentioned scopes. I personally like the 2-7x32mm scopes. They are all the scopes I think I need.
Scopes I use are the Nikon Pro Sport, Bushnell 3200 Elite, and I have a Sightron 1 which is also a good scope. If you need the bullet drop compensator then you would want to look at the Nikon Omega or one of the Burris maybe.
Leupold makes a lower end scope called the Rifleman but it has good glass, excellent clarity, and being a Leupold does not hurt it either. Although I was told they were made in China. Whether that is true I could not say.