The Powder Horn is a good scope with good glass; i've mounted a few and zeroed the rifles. Scope glass has improved greatly over the past 40 years. A 4X Simmons has better glass than some expensive scopes i bought in the 60s and 70s.

My guns get bounced around uncased in my old hunting truck. In the past 12 years i've gone through a bunch of muzzleloader scopes: The 4X Simmons and the 4X Nikon Pro Staff held up better than the Bushnells and Tascos but they all eventually died.